Mutations in single genes cause thousands of diseases. On a chalkboard, it’s easy to change a single letter in a disease-causing DNA strand to eradicate disease. Professor Porteus demonstrates the progress towards editing the genome of stem cells to cure patients of disease, effectively turning this science fiction vision into reality. Matthew Porteus is an associate professor of pediatrics. He studies genome editing as therapy for children with genetic disorders. His research has enabled scientists to “edit” genes using a technology called CRISPR, which removes a singular bad gene. He attends at the Lucille Packard Children’s Hospital where he supervises children undergoing stem cell transplantation. Classes Without Quizzes are presented by the Stanford Alumni Association. This talk was filmed at Stanford Reunion Homecoming 2016.