Editor-at-Large Ushma Neill interviews Rudolf Jaenisch of MIT’s Whitehead Institute. Dr. Jaenisch created the first transgenic mice and conducted the first experiment demonstrating that therapeutic cloning could correct a genetic defect. Additionally, Jaenisch has been at the forefront of research on induced pluripotent stem cells and has shown that these cells can correct sickle cell anemia and Parkinson disease in rodents. In this interview, Jaenisch discusses his work as a postdoctoral fellow in Arnold Levine’s lab studying DNA replication with the tumor virus SV40, which led to his collaboration with developmental geneticist Beatrice Mintz. Additionally, Jaenisch discusses adoption of new methods and technologies to address interesting questions in genetics as well as the application of these technologies to humans.