In 1959, Roger Kornberg's father, Arthur Kornberg, received the Nobel Prize in Physiology or Medicine for studies of how genetic information moves from one DNA molecule to another. This is called DNA replication. Arthur Kornberg found the first enzyme that could make DNA. This was the first known enzyme to take its instructions from a DNA copy. Roger Kornberg's younger brother, Thomas Bill Kornberg, discovered DNA polymerases II and III in 1970 and is now a geneticist at the University of California, San Francisco. All three Kornbergs have worked to understand how genetic information is used in cells. Arthur and Roger Kornberg are the sixth father and son to win Nobel Prizes.