Ps challenged the constitutionality of the ban on compensation for human organs in the National Organ Transplant Act, as applied to bone marrow transplants. Ps seek declaratory and injunctive relief to allow harvesting of 'hematopoietic stem cells' extracted by 'peripheral blood stem cell apheresis.' None of the bone marrow is extracted but bone marrow stem cells and simply filtered from the blood of a matching donor. 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. Ps propose 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. Ps argue that the National Organ Transplant Act 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.' A bone marrow donor undergoing apheresis suffers no permanent harm, experiences no significant risk, and quickly regenerates what is donated. Ps argue that any rational basis that Congress had when it passed the statute no longer exists because of the subsequent development of the apheresis method. Ps seek declaratory and injunctive relief. The court dismissed under Fed. R. Civ. P. 12(b)(6). Ps appealed.