On Sept. 6, 1978, Genentech, the most successful of the new biotech start-up companies, announced that scientists at the firm had successfully cloned the gene encoding human insulin in Escherichia coli bacteria.

In 1982, the U.S. Food and Drug Administration (FDA) approved human insulin and it was on the market by 1983. Since then, millions of people have used the medicine, and it has almost completely replaced insulin created from animals.