Robert Klein convinced Californians to part with $3 billion of their taxes to fund stem cell research. Proposition 71, the state referendum he championed, was handily passed by state voters in 2004, creating the largest source of embryonic stem cell funding in the world.

Klein, a Stanford-educated lawyer, transformed himself into a full-time medical research activist from a real estate investment banker after his son Jordan was diagnosed with juvenile diabetes in 2001. Now he’s the chairman of the Independent Citizens Oversight Committee (ICOC), the 29-member body that oversees the California Institute for Regenerative Medicine (CIRM), the state agency created by his proposition.