Cell Stem Cell doi:10.1016/j.stem.2009.09.012 (2009)

Adult cells can be turned into 'pluripotent' or embryonic-like stem cells with the insertion of four genes — Sox2, Oct4, Klf4 and c-Myc. However, this method is not clinically useful because c-Myc and Sox2 have been linked to cancer and the viral vectors used to transfer those genes are also cancer-promoting.

Using chemical screening, Lee Rubin and Kevin Eggan at Harvard University in Cambridge, Massachusetts, and their colleagues discovered a small molecule, which they call RepSox, that essentially does the jobs of c-Myc and Sox2. Mouse cells expressing only Klf4 and Oct4 became pluripotent after treatment with RepSox.

This may be a step towards chemical cell reprogramming that avoids gene transfer altogether.