Ricki Lewis | Jan 21, 2001 | 5 min read
Most media reports on stem cell biology trace the field's origin to two key papers published in 1981.1,2 But Leroy Stevens at the Jackson Laboratory in Bar Harbor, Maine, laid the groundwork in mice from the 1950s through the 1970s, manipulating bizarre growths called embryoid bodies,3 to see what these cells would become. Embryoid bodies formed when cancer cells were transplanted into mouse abdomens. At first they appeared to be a ring of cells enclosing blood, debris, and a few unspecialized c