N. Engl. J. Med. 359, 2641–2650 (2008)

RNA interference, in which cells use short stretches of RNA to block the translation of genetic recipes into proteins, has been linked to survival in the largest study yet to examine the effect of this phenomenon on human cancers.

A team led by Anil Sood of the University of Texas M. D. Anderson Cancer Center in Houston measured gene expression levels of Dicer and Drosha, proteins involved in the interference pathway, in 111 invasive ovarian tumours. Women with high levels of both proteins survived for a median of more than 11 years — more than four times longer than those with low levels.

The findings were verified using a second set of 132 ovarian cancer samples. For lung cancer and breast cancer, only Dicer levels affected survival. The findings could lead to the development of better prognostic tests and therapies.