The SIRT1 protein is needed to lengthen and maintain telomeres during cell reprogramming, new research demonstrates. SIRT1 also guarantees the integrity of the genome of stem cells that come out of the cell reprogramming process; these cells are known as induced pluripotent stem cells. The study sheds light on how cell reprogramming guarantees the healthy functioning of stem cells. This knowledge will help to overcome barriers that come out of the use of iPS cells so they may be used in regenerative medicine.