Two items: a glossy 5 x 7 photo of Edward Tatum, who shared the Nobel Prize in Physiology or Medicine in 1958 for showing that genes control individual steps in metabolism, signed in black ink, "E. L. Tatum"; and a glossy 8 x 10.25 photo of Howard Martin Temin, who discovered reverse transcriptase and shared the 1975 Nobel Prize in Physiology or Medicine, signed in black felt tip, "Howard M. Temin." In overall fine condition.