Asuperb lesson on patents in general and the grotesque American patent system in particular. Everyone agrees that patents are essential to allow inventors to profit from their inventions, but what is “patentable” remains a subject of fierce debate, notes Contreras, who teaches intellectual property, science policy, and the law and ethics of genetics at the University of Utah. New machines, methods, or materials qualify, but naturally occurring substances don’t. As such, a botanist who discovers a previously unknown mushroom can’t patent it because he only found it; he didn’t invent it. Yet, somehow, genes qualify. During the 1970s and ’80s, genetic engineering exploded when courts began approving patents for genetically modified organisms, and entrepreneurs pushed the envelope by asking for and receiving patents on sequences of human DNA. “By late 1996,” writes Contreras, “the journal Nature reported that more than 350 new gene patent applications had been filed. Genes that could help to diagnose predispositions to more and more health conditions.” There was no shortage of religious and scientific argument in opposition, but gene patents were legal, and changing a law requires legal arguments. Although it had never litigated a patent case, the ACLU decided in 2009 to take action and chose a target to maximize public interest. It focused on a woman who had a gene that put her at increased risk of developing breast or ovarian cancer, the test for which was in the hands of a company that owned the patent, monopolized the diagnostic test, and set a high price that insurance often did not cover. Having set the scene, Contreras assembles a large cast of lawyers, judges, activists, scientists, and patients and engagingly describes four years of tortuous legal action that saw victory in federal court, reversal on appeal, and a final triumph in the Supreme Court. A detailed account of patent law that, against all odds, turns out to be fascinating.