While the promise of a stem-cell treatment to treat disease remains far off, scientists continue to take giant steps toward bringing that potential from the lab to the clinic. Working with the groundbreaking type of stem cell known as induced pluripotent stem (iPS) cells which can be generated from a skin cell, completely bypassing the need for embryos researchers at Children's Hospital Boston have overcome a critical hurdle in making the technology safe for human patients. Until now, to create iPS cells from skin cells, researchers needed to expose the skin cells to both viruses and cancer-causing genes to reprogram them to an embryo-like state. Now the Boston scientists report success in using another form of the added genes, known as RNA, that eliminates the danger posed by the insertion of the viruses and cancer-promoting genes. And as an unexpected bonus, the technique is about 100 times more efficient in making iPS cells than the older method. The new findings mark a significant advance toward someday using stem cells as a source of new and healthy cells to replace those that have been destroyed by disease.