                 FOR PUBLICATION
 UNITED STATES COURT OF APPEALS
      FOR THE NINTH CIRCUIT

DOREEN FLYNN; AKIIM DESHAY;          
MIKE HAMEL; MARK HACHEY;
KUMUD MAJUMDER;
MOREMARROWDONORS.ORG; JOHN                 No. 10-55643
WAGNER, M.D.,                                D.C. No.
            Plaintiffs-Appellants,
                                         2:09-cv-07772-
                 v.                         VBF-AJW
ERIC HOLDER Jr., Attorney General            OPINION
of the United States, sued in his
Official Capacity,
               Defendant-Appellee.
                                     
      Appeal from the United States District Court
           for the Central District of California
     Valerie Baker Fairbank, District Judge, Presiding

                  Argued and Submitted
         February 15, 2011—Pasadena, California

                 Filed December 1, 2011

   Before: Alfred T. Goodwin, Andrew J. Kleinfeld, and
             Susan P. Graber, Circuit Judges.

               Opinion by Judge Kleinfeld




                          20553
20556                      FLYNN v. HOLDER


                               COUNSEL

Jeff Rowes, Institute for Justice, Arlington, Virginia, for the
appellants.

Helen L. Gilbert, U.S. Department of Justice, Washington,
D.C., for the appellee.

Aneal R. Ganta, Gibson, Dunn & Crutcher LLP, Irvine, Cali-
fornia, for the amici curiae.


                               OPINION

KLEINFELD, Senior Circuit Judge:

  This is a challenge to a criminal statute prohibiting com-
pensation for “bone marrow” donations.1

                               I.   Facts.

   The district court dismissed the complaint for failure to
state a claim upon which relief could be granted.2 We take the




  1
   42 U.S.C. § 274e.
  2
   Fed. R. Civ. P. 12(b)(6).
                           FLYNN v. HOLDER                        20557
facts from the allegations in the complaint to determine
whether, if proved, they would state an actionable claim.3

   The complaint challenges the constitutionality of the ban on
compensation for human organs in the National Organ Trans-
plant Act, as applied to bone marrow transplants.4 Plaintiffs
seek declaratory and injunctive relief to allow harvesting of
“hematopoietic stem cells.” The complaint is not crystal clear
on whether plaintiffs claim that compensation for all bone
marrow transplantation is constitutionally protected, but the
focus of the arguments is on cells extracted by “peripheral
blood stem cell apheresis.” This is a relatively new method of
bone marrow transplant that avoids the need to invade the
bone for marrow.

   Some plaintiffs are parents of sick children who have dis-
eases such as leukemia and a rare type of anemia, which can
be fatal without bone marrow transplants. Another plaintiff is
a physician and medical school professor, and an expert in
bone marrow transplantation. He says that at least one out of
five of his patients dies because no matching bone marrow
donor can be found, and many others have complications
when scarcity of matching donors compels him to use imper-
fectly matched donors. One plaintiff is a parent of mixed race
children, for whom sufficiently matched donors are especially
scarce, because mixed race persons typically have the rarest
marrow cell types. One plaintiff is an African-American man
suffering from leukemia who received a bone marrow trans-
plant from his sister. She was an imperfect match and, though
the transplant saved his life, he continues to suffer from life-
threatening and disabling complications on account of the
slight genetic mismatch.
  3
     Newcal Indus., Inc. v. Ikon Office Solution, 513 F.3d 1038, 1043 n.2
(9th Cir. 2008).
   4
     42 U.S.C. § 274e.
20558                  FLYNN v. HOLDER
   Another plaintiff is a California nonprofit corporation that
seeks to operate a program incentivizing bone marrow dona-
tions. The corporation proposes to offer $3,000 awards in the
form of scholarships, housing allowances, or gifts to charities
selected by donors, initially to minority and mixed race
donors of bone marrow cells, who are likely to have the rarest
marrow cell type. The corporation, MoreMarrowDonors.org,
alleges that it cannot launch this program because the
National Organ Transplant Act criminalizes payment of com-
pensation for organs, and classifies bone marrow as an organ.5

   We generally use the word “marrow” to refer to the soft,
fatty material in the central cavities of big bones, what some
people suck out of beef bones. Bone marrow is the body’s
blood manufacturing factory. Bone marrow transplants enable
sick patients, whose own blood cells need to be killed to save
their lives, to produce new blood cells. For example, patients
with leukemia, which is cancer of the blood or bone marrow,
may need chemotherapy or radiation to kill the cancer cells in
their blood. The treatments kill the white blood cells essential
to their immune systems. The patients will die if the killed
cells are not quickly replaced with healthy cells. And they
cannot be replaced without the stem cells, which we describe
below, that can mature into white blood cells. These stem
cells can only be obtained through bone marrow transplants.

   Until about twenty years ago, bone marrow was extracted
from donors’ bones by “aspiration.” Long needles, thick
enough to suck out the soft, fatty marrow, were inserted into
the cavities of the anesthetized donor’s hip bones. These are
large bones with big central cavities full of marrow. Aspira-
tion is a painful, unpleasant procedure for the donor. It
requires hospitalization and general or local anesthesia, and
involves commensurate risks.
  5
   Id.
                         FLYNN v. HOLDER                          20559
   The complaint explains that a new technology has super-
seded this technique during the last twenty years, after enact-
ment of the National Organ Transplant Act. With this new
technique, now used for at least two-thirds of bone marrow
transplants, none of the soft, fatty marrow is actually donated.
Patients who need bone marrow transplants do not need
everything that the soft, fatty substance from bone cavities
contains, just some of the marrow’s “hematopoietic stem
cells.” These stem cells are seeds from which white blood
cells, red blood cells, and platelets grow.

   These are not the embryonic stem cells often the subject of
controversy. Those stem cells, taken from human embryos,
are “pluripotent,” that is, they can turn into any kind of cell
— brain, blood, retina, toenail, whatever.6 The stem cells at
issue in this case are “hematopoietic stem cells.” “Hema”
refers to blood, and “poietic” means “pertaining to production.”7
Hematopoietic stem cells turn into blood cells and nothing
else. Humans and other large mammals produce these blood
stem cells constantly in vast numbers, because our blood cells
die within a few months and need continual replacement.8 The
dead blood cells are flushed out in the spleen, the body’s gar-
bage disposal for used-up blood cells,9 and new ones are made
in the bone marrow, as long as we live.

   Most blood stem cells stay in the bone marrow cavity and
grow into mature blood cells there, before passing into the
blood vessels. But some blood stem cells flow into and circu-
late in the bloodstream before they mature. These are called
“peripheral” blood stem cells, “peripheral” meaning outside
the central area of the body.10 The new bone marrow donation
  6
    Taber’s Cyclopedic Medical Dictionary 1809 (21st ed. 2009).
  7
    Id. at 1033, 1819.
  8
    See id. at 284.
  9
    See id. at 2177.
  10
     Id. at 1752.
20560                   FLYNN v. HOLDER
technique, developed during the past twenty years, is called
“peripheral blood stem cell apheresis.” “Apheresis” means the
removal or separation of something.11 This procedure begins
with five days of injections of a medication called a “granulo-
cyte colony-stimulating factor” into the donor’s blood. The
medication accelerates blood stem cell production in the mar-
row, so that more stem cells go into the bloodstream. Then,
with no need for sedatives or anesthesia, a needle is inserted
into the donor’s vein. Blood is withdrawn from the vein and
filtered through an apheresis machine to extract the blood
stem cells. The remaining components of the blood are
returned to the donor’s vein. The blood stem cells extracted
in the apheresis method are replaced by the donor’s bone mar-
row in three to six weeks. Complications for the donor are
exceedingly rare.

   The main difference between an ordinary blood donation
and apheresis is that instead of just filling up a plastic bag
with whole blood, the donor sits for some hours in a recliner
while the blood passes through the apheresis machine. This
same apheresis technique is sometimes used for purposes
other than bone marrow donations, such as when the machine
is set up to collect plasma or platelets, rather than stem cells,
from a donor’s blood. When it is used for these other pur-
poses, the identical technique is called a “blood donation” or
“blood plasma donation.” When used to separate out and col-
lect hematopoietic stem cells from the donor’s bloodstream,
apheresis is called “peripheral blood stem cell apheresis” or
a “bone marrow donation.”

  Though the new process makes bone marrow donations
much like ordinary blood donations, the matching problem
remains. Deep genetic compatibility is critical in bone mar-
row transplants, because our bodies are xenophobic: white
blood cells produced from a donor’s imperfectly matched
blood stem cells treat the recipient patient’s body as foreign,
  11
    Id. at 161.
                            FLYNN v. HOLDER               20561
attacking it. This is graft-versus-host disease, which can be
fatal or can result in lifelong medical problems for the trans-
plant recipient. All donations from another person, except for
one’s identical twin, produce at least some graft-versus-host
disease in the recipient, but the closer the genetic match, the
less disease. Matching is easy in ordinary blood transfusions,
because there are only four basic blood types. But there are
millions of marrow cell types, so good matches are hard to
find. The more diverse the patient’s genetic heritage, the rarer
the match. For example, African-Americans have especially
great difficulty finding a compatible unrelated donor, as they
tend to have a mix of African, Caucasian, and Native-
American genes, and fewer potential donors are registered in
the national civilian registry.

   The establishment of this registry, the National Marrow
Donor Program, which is funded by the federal government
to assist in finding matches, was an important part of the stat-
ute at issue here.12 But even with this registry, good matches
often cannot be found. And even when a good match is found
in the registry, tracking down the potential donor from what
may be an outdated address may be impossible to accomplish
in time to save the patient’s life—assuming the potential
donor is willing to go through with the process when found.

   The plaintiff nonprofit proposes to mitigate this matching
problem by using a financial incentive. The idea is that the
financial incentive will induce more potential donors to sign
up, stay in touch so that they can be located when necessary,
and go through with the donations. The nonprofit plans to
focus its attention initially on minority and mixed race donors,
because their marrow cell types are rarer. The financial incen-
tives would be $3,000 in scholarships, housing allowances, or
gifts to charities of the donor’s choice, which the nonprofit
  12
    See 42 U.S.C. § 274k.
20562                      FLYNN v. HOLDER
acknowledges would be “valuable consideration” under the
statutory prohibition.13

   Plaintiffs argue that the National Organ Transplant Act, as
applied to MoreMarrowDonor.org’s planned pilot program,
violates the Equal Protection Clause. They claim that blood
stem cell harvesting is not materially different from blood,
sperm, and egg harvesting, which are not included under the
statutory or regulatory definitions of “human organ.”14 Like
donors of blood and sperm, a bone marrow donor undergoing
apheresis suffers no permanent harm, experiences no signifi-
cant risk, and quickly regenerates what is donated. Plaintiffs
also argue that any rational basis that Congress had when it
passed the statute no longer exists with respect to the pilot
program, because of the subsequent development of the
apheresis method. Plaintiffs seek declaratory and injunctive
relief so that MoreMarrowDonors.org can proceed with the
initiative.

                            II.   Analysis.

     We review a 12(b)(6) dismissal de novo.15

A.     The arguments.

  The core of plaintiffs’ argument is that there is no rational
basis for allowing compensation for blood, sperm, and egg
donations, while disallowing compensation for bone marrow
donations, because bone marrow donations can now be
accomplished through apheresis without removing marrow,
and the donor’s body quickly regenerates the donated stem
cells. Since the distinction, they argue, is without a rational
  13
     42 U.S.C. § 274e(a).
  14
     See 42 U.S.C. § 274e(c)(1); 42 C.F.R. § 121.13 (2010).
  15
      Fed. R. Civ. P. 12(b)(6). Barker v. Riverside Cnty. Office of Educ.,
584 F.3d 821, 824 (9th Cir. 2009).
                           FLYNN v. HOLDER                        20563
basis, it violates the Equal Protection Clause, despite highly
deferential “rational basis” review.16

   [1] The Attorney General responds that the statute plainly
classifies “bone marrow” as an organ for which compensation
is prohibited, and that the congressional determination is
indeed rational. The statute makes it a felony “to knowingly
acquire, receive, or otherwise transfer any human organ for
valuable consideration for use in human transplantation.”17
And it defines the term “human organ” to include “bone mar-
row.”18 Ergo, the statute expressly prohibits compensating
bone marrow donors. According to the government’s brief,
Congress took the view that “human body parts should not be
viewed as commodities,”19 and had several policy reasons for
disallowing compensation to donors, which suffice to serve as
a rational basis for the prohibition.

   [2] As for plaintiffs’ argument that there is no rational
basis for a distinction between peripheral blood stem cell
apheresis and blood donations, the government argues that
because it is much harder to find a match for patients who
need bone marrow transplants than for patients who need
blood transfusions, exploitative market forces could be trig-
gered if bone marrow could be bought. The government also
asserts that peripheral blood stem cell apheresis poses greater
health risks for the donor than blood donations do, because of
the side effects of the medicine used to increase stem cell
secretion. The government bases this factual assertion on
information taken not from the complaint, which says that
  16
      See Kahawaiolaa v. Norton, 386 F.3d 1271, 1277-78 (9th Cir. 2004).
  17
      42 U.S.C. § 274e(a).
   18
      “The term ‘human organ’ means the human (including fetal) kidney,
liver, heart, lung, pancreas, bone marrow, cornea, eye, bone, and skin or
any subpart thereof and any other human organ (or any subpart thereof,
including that derived from a fetus) specified by the Secretary of Health
and Human Services by regulation.” Id. § 274e(c)(1).
   19
      Citing S. Rep. No. 98-382, at 17 (1984).
20564                      FLYNN v. HOLDER
there is no significant risk, but from a patient handout called
“Now That You Are a Match,” published by the National
Marrow Donor Program.20 Since the case was dismissed on a
12(b)(6) motion, the complaint controls.21 If material allega-
tions of fact are mistaken, summary judgment or trial can so
establish. We do not imply that patient risk is material to what
the statute means and whether the distinctions it draws are
constitutionally permissible. There are significant risks from
egg donations,22 but the government concedes that the statute
allows them. The statute does not prohibit trials of new medi-
cines, which often involve risks and create discomfort or
worse for participants. Other provisions of law and medical
ethics may address these concerns, but the statute before us
does not.

B.     Bone marrow transplants by aspiration.

   [3] Plaintiffs address their arguments largely to the periph-
eral blood stem cell apheresis method of extracting hemato-
poietic stem cells, but their complaint appears to challenge the
prohibition on bone marrow transplants regardless of method.
They do not, in their complaint or their brief, confine their
challenge to transplants by means of apheresis. They appar-
ently propose to give compensated donors the choice between
aspiration and apheresis. To the extent that plaintiffs chal-
lenge the constitutionality of the compensation ban on bone
marrow donation by the old aspiration method — where a
long needle is inserted into the cavity of the hip bone to
extract the soft, fatty marrow — the challenge must fail.
  20
      National Marrow Donor Program, Now That You Are a Match: What
You Need To Know About Becoming a Donor (2006).
   21
      Maktab Tarighe Oveyssi Shah Maghsoudi, Inc. v. Kianfar, 179 F.3d
1244, 1246 (9th Cir. 1999).
   22
      See Kara N. Maxwell et al., The Incidence of Both Serious and Minor
Complications in Young Women Undergoing Oocyte Donation, 90 Fertil-
ity and Sterility 2031, 2165 (2008).
                           FLYNN v. HOLDER                         20565
   [4] The statute says that the term “human organ” includes
“bone marrow.”23 The soft, fatty stuff that the needle extracts
is bone marrow. It is irrelevant that the legislative history
indicates that Congress viewed certain types of regenerable
tissue, such as blood, as falling outside the statutory definition
of “human organ.”24 It may be that senators themselves, their
staffs, or lobbyists for blood banks argued for an exception
for body substances that can regenerate, and persuaded com-
mittee staffers to put that reason in the legislative history. But
the statute does not say that compensation is permitted for
organs or body parts that regenerate and prohibited for those
that do not. Nor is the statute consistent with such a construc-
tion. The statute defines the liver “or any subpart thereof” as
an organ for which compensation is prohibited.25 The drafters
doubtless knew that a partial resection of a liver can yield a
donation that will save the recipient’s life, and that the
donor’s liver will grow back.26 So the statute does expressly
prohibit compensation for at least one explicitly denoted
“human organ” that will regenerate.

   [5] As for whether the distinction between the organs or
other body substances for which compensation is permitted
and those for which it is prohibited has a rational basis, there
are two classes of rational basis here: policy concerns and
philosophical concerns. The policy concerns are obvious.
Some are mentioned in the legislative history, though they
  23
      42 U.S.C. § 274e(c)(1).
  24
      See S. Rep. No. 98-382, at 16-17 (1984) (stating that the organ sale
prohibition was not “meant to include blood and blood derivatives, which
can be replenished and whose donation does not compromise the health
of the donor”); H.R. Rep. No. 98-1127, at 16 (1984) (Conf. Rep.) (stating
that “the term ‘human organ’ is not intended to include replenishable tis-
sues such as blood or sperm”).
   25
      42 U.S.C. § 274e(c)(1).
   26
      Pierre-Alain Clavien et al., Strategies for Safer Liver Surgery and
Partial Liver Transplantation, 356 New Eng. J. of Med. 1493, 1545
(2007).
20566                       FLYNN v. HOLDER
need not be.27 Congress may have been concerned that if
donors could be paid, rich patients or the medical industry
might induce poor people to sell their organs, even when the
transplant would create excessive medical risk, pain, or dis-
ability for the donor. Or, looking from the other end, Con-
gress might have been concerned that every last cent could be
extracted from sick patients needful of transplants, by well-
matched potential donors making “your money or your life”
offers.28 The existing commerce in organs extracted by force
or fraud by organ thieves29 might be stimulated by paying for
donations. Compensation to donors might also degrade the
quality of the organ supply, by inducing potential donors to
lie about their medical histories in order to make their organs
marketable.30 Plaintiffs argue that a $3,000 housing subsidy,
scholarship, or charitable donation is too small an amount to
create a risk of any of these evils, but for a lot of people that
could amount to three to six months’ rent.

   Congress may have had philosophical as well as policy rea-
sons for prohibiting compensation. People tend to have an
instinctive revulsion at denial of bodily integrity, particularly
  27
      “The government need not state its purposes at the time it acts. It is
sufficient that the government could have had a legitimate reason for act-
ing as it did.” Kim v. United States, 121 F.3d 1269, 1274 (9th Cir. 1997).
   28
      “[Bone marrow donors] are very difficult to match with recipients, . . .
[and bone marrow donations] may represent a last resort to potential recip-
ients.” H.R. Rep. No. 98-1127, at 17 (1984) (Conf. Rep.).
   29
      See Sally Satel, The Market for Kidneys, Livers and Lungs, Wall St.
J., Nov. 8, 2011, at A17.
   30
      See National Organ Transplant Act: Hearing on H.R. 4080 Before the
Subcomm. on Health of the H. Comm. on Ways & Means, 98th Cong., 2d
Sess. 26 (1984) (statement of Rep. Waxman) (“If [people are allowed to
sell their kidneys], I believe our efforts to promote voluntary organ dona-
tions would collapse, and health risks to transplant patients would greatly
increase. Human organs should not be treated like fenders in an auto junk-
yard.”). See also Maurice McGregor, Pragmatic Altruism, 160 Can. Med.
Ass’n J. 5, 91 (1999) (“The need for money is a disincentive to honest dis-
closure, a disincentive whose force will increase with the strength of the
need.”).
                            FLYNN v. HOLDER                          20567
removal of flesh from a human being for use by another, and
most particularly “commodification” of such conduct,31 that
is, the sale of one’s bodily tissue.32 While there is reportedly
a large international market for the buying and selling of
human organs,33 in the United States, such a market is crimi-
nal and the commerce is generally seen as revolting. Leon
Kass examines the philosophical issue of commodification
with his observation that nonprofit hospitals, donor registries,
and physicians are permitted to make a lot of money from
organ transplants, and the only people who get nothing are
those whose organs are donated:

       [A]lthough we allow no commerce in organs, trans-
       plant surgeons and hospitals are making handsome
       profits from the organ-trading business, and even the
       not-for-profit transplant registries and procurement
       agencies glean for their employees a middleman’s
       livelihood. Why . . . should everyone be making
       money from this business except the person whose
       organ makes it possible? Could it be that [the] real
       uneasiness [lies] with organ donation or with trans-
       plantation itself, for if not, what would be objection-
       able about its turning a profit?34

Kass suggests that the revulsion for commodification of
human flesh is reflected in our language:35 we call donors who
are paid for their organs “donors” rather than “sellers” or
“vendors.” To account for why most of us are revolted by the
notion of a poor person selling a kidney to feed his family,
  31
      See S. Rep. No. 98-382, at 17 (1984) (“[H]uman body parts should not
be viewed as commodities[.]”).
   32
       See Coyote Publ’g, Inc. v. Miller, 598 F.3d 592, 603 (9th Cir. 2010),
cert. denied, 131 S. Ct. 1556 (2011).
   33
      See Satel, supra note 29.
   34
      Leon R. Kass, Life, Liberty and the Defense of Dignity: The Challenge
for Bioethics 177 (2002).
   35
      See id. at 195.
20568                       FLYNN v. HOLDER
Kass cites the taboos we have against cannibalism, defilement
of corpses, and necrophilia.36 Kass points to the idea of “psy-
chophysical unity, a position that regards a human being as
largely, if not wholly, self-identical with his enlivened body,”
so that, as Kant put it, to “ ‘dispose of oneself as a mere
means to some end of one’s own liking is to degrade the
humanity in one’s person.’ ”37 In this view, “organ transplan-
tation . . . is — once we strip away the trappings of the sterile
operating rooms and their astonishing technologies — simply
a noble form of cannibalism.”38

   [6] These reasons are in some respects vague, in some
speculative, and in some arguably misplaced. There are strong
arguments for contrary views.39 But these policy and philo-
sophical choices are for Congress to make, not us. The dis-
tinctions made by Congress must have a rational basis, but do
not need to fit perfectly with that rational basis, and the basis
need merely be rational, not persuasive to all.40 Here, Con-
gress made a distinction between body material that is com-
pensable and body material that is not. The distinction has a
rational basis, so the prohibition on compensation for bone
marrow donations by the aspiration method does not violate
the Equal Protection Clause.
  36
      Id. at 183.
  37
      Id. at 181-82, 185.
   38
      Id. at 185.
   39
      See, e.g., Virginia Postrel, . . . With Functioning Kidneys For All, The
Atlantic, July 9, 2009, http://www.theatlantic.com/magazine/archive/
2009/07/with-functioning-kidneys-for-all/7587.
   40
      See Heller v. Doe, 509 U.S. 312, 321 (1993) (stating that “courts are
compelled under rational-basis review to accept a legislature’s generaliza-
tions even when there is an imperfect fit between means and ends . . . [and
a] classification does not fail rational-basis review because it is not made
with mathematical nicety” (internal quotation marks omitted)); Doe v.
United States, 419 F.3d 1058, 1063 (9th Cir. 2005).
                           FLYNN v. HOLDER                         20569
C.   Bone marrow transplants by apheresis.

   [7] The focus, though, of plaintiffs’ arguments is compen-
sation for “bone marrow donations” by the peripheral blood
stem cell apheresis method. For this, we need not answer any
constitutional question, because the statute contains no prohi-
bition. Such donations of cells drawn from blood flowing
through the veins may sometimes anachronistically be called
“bone marrow donations,” but none of the soft, fatty marrow
is donated, just cells found outside the marrow, outside the
bones, flowing through the veins.

  [8] Congress could not have had an intent to address the
apheresis method when it passed the statute, because the
method did not exist at that time. We must construe the words
of the statute to see what they imply about extraction of
hematopoietic stem cells by this method. This issue has not
been addressed by any of our sister circuits.41

   [9] Since payment for blood donations has long been com-
mon, the silence in the National Organ Transplant Act on
compensating blood donors is loud. “Blood” is omitted from
the list of examples of “human organs” in the statute and the
regulation. The statute says “human organ” is defined as a
human “kidney, liver, heart, lung, pancreas, bone marrow,
cornea, eye, bone, and skin or any subpart thereof and any
   41
      We have cited the National Organ Transplant Act in other contexts.
See Newman v. Sathyavaglswaran, 287 F.3d 786, 794 (9th Cir. 2002);
Coyote Publ’g, Inc. v. Miller, 598 F.3d 592, 603 (9th Cir. 2010). Some
district courts have considered related questions in the context of insur-
ance claims. See Nesseim v. Mail Handlers Benefit Plan, 792 F. Supp.
674, 678 (D.S.D. 1992), rev’d, 995 F.2d 804, 807 (8th Cir. 1993); Duck-
witz v. Gen. Am. Life Ins. Co., 812 F. Supp. 864, 867 (N.D. Ill. 1993);
Healthcare Am. Plans, Inc. v. Bossemeyer, 953 F. Supp. 1176, 1185 (D.
Kan. 1996). No decision by any court addressing whether the National
Organ Transplant Act prohibits compensation for hematopoietic stem
cells, or anything analogous, has been cited to us, and we have found
none.
20570                     FLYNN v. HOLDER
other human organ . . . specified by the Secretary of Health
and Human Services by regulation.”42 The regulation adds
intestines and the rest of the gastrointestinal tract to the list:
“kidney, liver, heart, lung, pancreas, bone marrow, cornea,
eye, bone, skin, and intestine, including the esophagus, stom-
ach, small and/or large intestine, or any portion of the gastro-
intestinal tract.”43 Neither the statute nor the regulation
defines “human organ” to include “blood.” The government
concedes that the common practice of compensating blood
donors is not prohibited by the statute.

   The government argues that hematopoietic stem cells in the
veins should be treated as “bone marrow” because “bone mar-
row” is a statutory organ, and the statute prohibits compensa-
tion not only for donation of an organ, but also “any subpart
thereof.”44 Hematopoietic stem cells are formed in the bone
marrow, and most are found there because they generally
mature into blood cells and platelets in the marrow. There-
fore, the government argues, they should be viewed as “sub-
parts” of the bone marrow, even when these stem cells are
obtained through apheresis, which is to say, from blood flow-
ing through veins.

   We reject this argument, because it proves too much, and
because it construes words to mean something different from
ordinary usage. If the government’s argument that what
comes from the marrow is a subpart of the marrow were cor-
rect, then the statute would prohibit compensating blood
donors. The red and white blood cells that flow through the
veins come from the bone marrow, just like hematopoietic
stem cells. But the government implicitly concedes that these
red and white blood cells are not “subparts” of bone marrow
under the statute, because it explicitly concedes that the stat-
ute does not prohibit compensation for blood donations.
  42
     42 U.S.C. § 274e(c)(1).
  43
     42 C.F.R. § 121.13 (2010).
  44
     42 U.S.C. § 274e(c)(1).
                          FLYNN v. HOLDER                       20571
   [10] As for ordinary usage, the bloodstream consists of
plasma containing red cells, white cells, platelets, stem cells
that will mature into one of these, and other material. We call
this liquid as a whole “blood.” No one calls it “bone marrow,”
even though these cells come from the marrow. There is no
reason to think that Congress intended “bone marrow” to
mean something so different from ordinary usage. Also, the
blood contains not only blood cells and stem cells, but also
other substances that come from elsewhere in the body. For
example, the blood contains vitamin B12, which enters the
bloodstream after binding with intrinsic factor and being
absorbed from the small intestine.45 The government’s argu-
ment would treat vitamin B12 as a “subpart” of the intestines,
and the regulation prohibits paying donors for their intestines
or subparts thereof.46 But every blood draw contains some
vitamin B12, and we still call the red liquid “blood,” not
“guts.”

   Likewise, every blood draw includes some hematopoietic
stem cells. All that differentiates the blood drawn in periph-
eral blood stem cell apheresis from the blood drawn from a
compensated blood donor, other than the filtration process, is
the medicine given to donors in the days before the blood
draw to increase hematopoietic stem cell secretion. Once the
stem cells are in the bloodstream, they are a “subpart” of the
blood, not the bone marrow. The word “subpart” refers to the
organ from which the material is taken, not the organ in which
it was created. Taking part of the liver for a liver donation
would violate the statute because of the “subpart thereof” lan-
guage. But taking something from the blood that is created in
the marrow takes only a subpart of the blood.

   [11] We construe “bone marrow” to mean the soft, fatty
substance in bone cavities, as opposed to blood, which means
the red liquid that flows through the blood vessels. The statute
  45
    Harrison’s Principles of Internal Medicine 601-02 (16th ed. 2005).
  46
    42 C.F.R. § 121.13 (2010).
20572                 FLYNN v. HOLDER
does not prohibit compensation for donations of blood and the
substances in it, which include peripheral blood stem cells.
The Secretary of Health and Human Services has not exer-
cised regulatory authority to define blood or peripheral blood
stem cells as organs. We therefore need not decide whether
prohibiting compensation for such donations would be uncon-
stitutional.

                     III.   Conclusion.

   [12] It may be that “bone marrow transplant” is an anach-
ronism that will soon fade away, as peripheral blood stem cell
apheresis replaces aspiration as the transplant technique,
much as “dial the phone” is fading away now that telephones
do not have dials. Or it may live on, as “brief” does, even
though “briefs” are now lengthy arguments rather than, as
they used to be, brief summaries of authorities. Either way,
when the “peripheral blood stem cell apheresis” method of
“bone marrow transplantation” is used, it is not a transfer of
a “human organ” or a “subpart thereof” as defined by the stat-
ute and regulation, so the statute does not criminalize com-
pensating the donor.

  REVERSED. The judgment is VACATED and the case
REMANDED for such additional proceedings as may be
appropriate. Costs on appeal awarded to Plaintiffs-Appellants.
