In 1981, Frank Ruddle from Yale University, Frank Costantini and Elizabeth Lacy from Oxford, and Ralph L. Brinster and Richard Palmiter in collaboration from the University of Pennsylvania and the University of Washington injected purified DNA into a single-cell mouse embryo utilizing techniques developed by Brinster in the 1960s and 1970s, showing transmission of the genetic material to subsequent generations for the first time.

Concurrently, there was considerable excitement in cancer research, with the continuing discoveries and molecular cloning of viral and then cellular oncogenes. These genes were causally implicated in particular natural cancers and demonstrably capable of inducing transformation of cultured cells that would form tumors when transplanted in appropriate host animals.