Together with fellow American pharmacologists Robert Furchgott and Louis Ignarro, Murad received the 1998 Nobel Prize in Physiology or Medicine for discoveries related to the role of nitric oxide as a signaling molecule in the cardiovascular system.

Not to be confused with nitrous oxide (a gas used in anesthesia), nitric oxide is a colorless, odorless gas that, thanks to initial work by these three Nobel laureates and a flurry of subsequent research by others, now has widespread potential including the treatment of heart disease, shock, cancer, impotence, and pulmonary hypertension--a potentially fatal condition in premature infants. In 1994, the respected journal Science declared nitric oxide as its "molecule of the year."

Born in Whiting, Indiana, Murad studied medicine and pharmacology simultaneously at Western Reserve University, receiving both his M.D. and Ph.D. in 1965. He was an intern and resident in internal medicine at Massachusetts General Hospital until 1967, and then...