Organ market advocates are at “both a win and a loss” after a California appeals court ruled on Dec. 2 that bone marrow could be sold on the market, according to a legal expert.

The ruling toppled a decades-long interpretation of National Organ Transplant Act, a U.S. law that has long made selling bone marrow a crime that is punishable for up to five years.

However, the bone marrow market could be easily eliminated if lawmakers oppose it, said Glenn Cohen, an assistant professor at Harvard wrote in the New England Journal of Medicine on Thursday.

In the case Flynn v. Holder, the U.S. Court of Appeals for the Ninth Circuit held that the federal law that bans buying and selling bodily organs but not fluids such as blood or semen does not apply to bone marrow.

However, the California case was really challenge on NOTA, the federal law that expressly includes “bone marrow” as a body part that cannot be sold. Petitioners said that the act was inherently unconstitutional because it violated part of the 14th Amendment. The Equal Protection Clause of the U.S. Constitution prohibits the federal and state governments from denying any person the equal protection of the law.

The court rejected the plaintiffs’ wider theory that it is their constitutional right to sell substances with substantial similarity to blood, sperm or eggs. So unless, organ market advocates of other body parts can find applicable statutory gaps similar to that regarding “peripheral-blood stem cells”, their claim will probably fail, Cohen wrote.

However the San Francisco-based court did decide that for the purposes of the NOTA, peripheral blood stem cells should be considered blood parts, not organ parts because technological breakthroughs have made donating bone marrow a process that is nearly identical to giving blood.

Cohen explained that the decision marks a “narrow win” for the plaintiffs because it was only achieved through a “statutory interpretation of NOTA, and Congress can always change the law by adding the words ‘peripheral-blood stem cells,’” Cohen wrote.

In the past, donating bone marrow was a very painful process in which a needle pierces through the pelvic bone to suck out the liquid marrow. Currently the majority of marrow donations are not actually donations of marrow. Peripheral blood stem cells are isolated from circulating blood and are developed into bone marrow in the recipient.

With the new ruling it is legal for approximately 70 percent of bone marrow donors to be paid up to $3,000 in scholarships, housing allowances or other incentives, according to a California non-profit