Should human DNA be patentable? That's the central question in Association for Molecular Pathology v. Myriad Genetics, a case argued before the U.S. Supreme Court in April. The lawsuit was organized by the American Civil Liberties Union on behalf of several professional organizations that have long opposed such patents, which the U.S. Patent and Trademark Office has been granting since the 1980s. Patent law is arcane, and arguments about it can sound a lot like squabbling over the number of angels that can dance on the head of a pin. But in this case, writes Science Correspondent Ronald Bailey, it affects tens of billions of dollars in research, products, and profits.