SCOTUS struck down patents on naturally occurring gene sequences themselves and decided that the &quot;mere isolation&quot; thereof cannot be patented:<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Ass%27n_for_Molecular_Pathology_v._Myriad_Genetics,_Inc.#Decision_of_the_Supreme_Court" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Ass%27n_for_Molecular_Patholog...</a><p>However, &quot;artificial&quot; sequences can be. I&#x27;m not aware of any test cases that establish boundaries on the difference though. It would be logical to assume you&#x27;d have to alter the nucleotide sequence to the extent that the resulting peptide or protein is not naturally occurring (e.g. changing a TTT codon to TTC wouldn&#x27;t suffice, since both will ultimately be translated into phenylalanine).<p>Contrary to this reasoning, complementary DNA <i>is</i> patentable in the US on the grounds that it&#x27;s &quot;not naturally occurring&quot;. So, if you take the mRNA corresponding to an un-patentable DNA sequence and mix it with a few enzymes and nucleotides that react in a deterministic fashion, you can then patent the sequence of the final product:<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Complementary_DNA" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Complementary_DNA</a><p>In a gross oversimplification, it&#x27;s almost as if the court said: &quot;you can&#x27;t patent natural English words, but you can patent the ROT13 versions of them&quot;.<p>But regarding methods, the majority opinion clearly said they&#x27;re fair game (just as you can&#x27;t patent gold, but you could patent a novel approach to mining or extracting it) and there are several valid examples in the US today:<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Biological_patents_in_the_United_States#Gene_patents" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Biological_patents_in_the_Unit...</a>