Jzubrovich at English Wikipedia · CC BY 3.0

Furchgott discovered in 1978 that blood vessels relax through a signal released by their own inner lining, and spent the following years identifying that mysterious compound as nitric oxide — a gas the body uses as a messenger, a finding that reshaped cardiovascular medicine and explained why nitroglycerin has treated angina for a century. He shared the 1998 Nobel Prize in Physiology or Medicine with Louis Ignarro and Ferid Murad. He kept working into his nineties, dying in 2009 at 92.