  The policy of the U.S. Patent and Trademark Office (PTO) used to be that life forms, as products of nature, were unpatentable. Only products and processes invented by humans could be patented. But what about genetically modified life forms: are they invented or discovered, the product of nature or humans? In 1980, the U.S. Supreme Court issued its 5–4 decision in Diamond v Chakrabarty that a bacterial strain that had been genetically modified to clean up oil spills could be patented since it was “man-made” and not naturally occurring. Since this ruling, “the PTO has awarded thousands of patents on biological products, including patents on genes, SNPs, ESTs, cell lines, mice, plants, rhesus monkeys, and human stem cells” (Resnik 2004, p.  54).[37] Following Diamond v Chakrabarty, genes and gene products are considered patentable in their non-naturally-occurring forms, even if, unlike genetically modified life forms, the sequence information they contain is unaltered from what occurs  naturally.[38] Patents are granted on cloned genes because they are isolated and purified versions of their naturally occurring state; patents are granted on cDNAs because they are not found in nature (without intervening introns) but produced using RNA molecules and the enzyme reverse transcriptase; and patents are granted on proteins, even if they occur naturally, when genetically engineered on the basis of DNA or RNA sequence data. For such cases, DNA sequences are treated by the PTO and U.S. Court of Appeals for the Federal Circuit as “compositions of matter” (the wording contained in the patent statute) analogous to patentable chemical compounds (Eisenberg  2002).[39]