Otha deWayne Howse · CC BY-SA 3.0

Stanley Cohen and Herbert Boyer were the first scientists to transplant genes between living organisms, launching the field of genetic engineering. Their technique underlies thousands of products including human growth hormone and the hepatitis B vaccine — without it, one immunologist said, "the face of biomedicine and biotechnology would look totally different." Boyer went on to co-found Genentech on their shared discovery; Cohen instead stayed on at Stanford as the Kwoh-Ting Li Professor, working as a consultant rather than a company founder.