Discovery of reverse transcriptase. "In 1969, Temin and a postdoctoral fellow, Satoshi Mizutani, began searching for the enzyme that was responsible for the phenomenon of viral RNA being transferred into proviral DNA. Later that year, Temin showed that certain tumor viruses carried the enzymatic ability to reverse the flow of information from RNA back to DNA using reverse transcriptase. Reverse transcriptase was also independently and simultaneously discovered in association with the murine leukemia virus by David Baltimore at the Massachusetts Institute of Technology.... Both scientists completed their initial work with RNA-dependent DNA polymerase with the Rous sarcoma virus." (Wikipedia article on Howard Martin Temin, accessed 3-2020).

In 1975 Temin shared the Nobel Prize in Physiology or Medicine with David Baltimore and Renato Dulbecco "for their discoveries concerning the interaction between tumour viruses and the genetic material of the cell."