Yamanaka on Stem Cells

Shinya Yamanaka tells the Los Angeles Times that he started working with induced pluripotent stem cells because the stem cell field was so competitive. "I decided to go the opposite direction — [turning body cells] back to the embryonic state," he says. While iPS cells get around the ethical issues of embryonic stem cells and the chance of immune rejection that comes along with embryonic stem cells, Yamanaka notes that the cells are made by retroviruses and can lead to tumor growth. "Scientists need to find out the methods to generate safer iPS cells, how to turn those cells into functional cells, and how to transplant resultant cells into a body. We also need to figure out how to use the cells to study diseases in the lab," he says.