Dr. Paul Knoepfler is an associate professor at UC Davis School of Medicine, where he does stem cell and cancer research. He also blogs at the Niche (http://www.ipscell.com) and is the author of two books: Stem Cells: An Insider's Guide and his new work GMO Sapiens, which covers CRISPR and human genetic modification for a lay audience. 
You can follow him on Twitter at  http://twitter.com/pknoepfler