On June 23, 2011, Yang Xu spoke to the CIRM governing board about research bottlenecks in induced pluripotent (iPS) stem cell biology. iPS cells are created from a person’s own tissue (eg skin) and yet have many characteristics of embryonic stem cells. It was assumed that iPS would not be rejected by a person’s immune system when they are transplanted back into that same individual. However, Dr. Xu presented research results done in mice that indicate re-transplantation of iPS can lead to rejection by the immune system. Xu is a professor of biology at the University of California, San Diego and has a CIRM Early Translation grant.