Scientists who recently turned skin into embryonic stem cells are now tweaking the process to reduce cancer risk, Reuters reports. A team at Kyoto University grew live mice with a cell cocktail, but said the rodents grew tumors. So they nixed a gene called c-Myc1 and the next batch came out tumor-free. They have also made human cells without the cancer-causing element.
But the cancer-free cell cocktail made mice only half as well, they said, and admitted that tumors may crop up later—which means the skin cell method still needs refining, according to the Kyoto team and a University of Wisconsin in Madison group who also reported the skin cell breakthrough. In fact, many scientists still want to research with all stem cells, including those from human embryos.