The relationship between retroviral genes and oncogenes is described.
Nobel lecture given on December 8, 1989, by Professor J. Michael Bishop and published in Les Prix. Nobel 1989, printed in Sweden by Norstedts Tryckeri, Stockholm, Sweden 1990, republished here with the permission of the Nobel Foundation, the copyright holder. The companion manuscript is Retroviruses and Oncogenes I, by Harold E. Varmus, published in Bios. Rep. 10 No. 5