Korsmeyer, known as 'Stan' to all, was raised on a livestock farm in Illinois. He distinguished himself at the early age of 14 by showing a pair of hogs and winning the Governor's Trophy at the Illinois State Fair. Early on he studied for a career in veterinary medicine, but a wise veterinarian guided him into a career in medicine. He completed a BA in biology from the University of Illinois-Urbana (1972), and an MD at the University of Illinois-Chicago (1976). After a residency at the University of California, San Francisco, he became an associate and then a senior investigator at the National Cancer Institute.
During this time, along with others, he cloned the BCL2 gene (Bakhshi, M. et al. Cell 41, 899–906; 1985) and began studying how the protein product was involved in follicular lymphoma. After moving to Washington University in 1986 as a Howard Hughes Medical Institute investigator, Stan embarked on studies that would transform the landscape of cancer biology along with many other fields. Building on earlier work of Vaux, Cory and Adams (Vaux, D. L. et al. Nature 335, 440–442; 1988) he developed both transgenic and knockout mice that conclusively showed a role for Bcl2 in blocking cell death (McDonnell, T. J. et al. Cell 57, 79–88; 1989; Cell 75, 229–240; 1993). Moreover, Bcl2-expressing transgenic mice developed lymphoma, establishing inhibition of cell death as a new pathway in oncogenesis (McDonnell, T. J. Nature 349, 254–257; 1991). His laboratory established that Bcl2 was a mitochondrial protein (Hockenbery, D. M. Nature 348, 334–336; 1990) that interacted with and inhibited another class of Bcl2 homologues — including proapoptotic proteins such as Bax — preventing mitochondrial permeabilization, cytochrome c and caspase activation, and ultimately cell death (Oltvai, Z. Cell 74, 609–619; 1993). He popularized the notion that the Bcl2 family homo- and heterodimers function as rheostats controlling cell death and survival. His laboratory went on to clone many other Bcl2 family members and defined pathways that were pivotal to not only cancer biology but several other fields including immunology, neuronal survival, chemotherapeutic action, and oxidant-induced stress. In 1998 he was recruited from his post as director of the Division of Molecular Oncology at Washington University to the Dana Farber Cancer Institute, where he served as the Sidney Farber professor of pathology and professor of medicine at Harvard Medical School.