On 5 January, the US Patent and Trademark Office (USPTO; Washington, DC) finally released revised guidelines concerning the “utility” and “written description” requirements for gene-based patents. As outlined in the December 1999 interim guidelines (Nat. Biotechnol. 18, 921, 2000), patent applicants are now required to show specific, credible, and substantial utility for gene sequences. Notably, isolated genes, isolated DNA, and expressed sequence tags (ESTs) can be patented if sufficient utility is described, and the DNA patent claim scope need not be limited to disclosed uses; in silico homology-based assertions of utility will be decided upon a case-by-case basis.