In Science today, Kyle Jensen and Fiona Murray at Massachusetts Institute of Technology calculated the proportion of human genes that had been patented by comparing the genetic sequences claimed in US patents to genes listed in the National Centre for Biotechnology Information gene database. They found that nearly 20% of the human genome, or 4,382 of the known 23, 688 human genes, have been patented, with over half owned by private companies. Around 63% of the patents are assigned to private firms, with one firm, Incyte Pharmaceuticals/Incyte Genomics, having intellectual property rights covering 2,000 human genes.