The Nobel Prize in Physiology or Medicine 1998 was awarded jointly to Robert F. Furchgott, Louis J. Ignarro and Ferid Murad "for their discoveries concerning nitric oxide as a signalling molecule in the cardiovascular system."
Louis J Ignarro, pharmacologist in Los Angeles, participated in the quest for EDRF's chemical nature. He performed a brilliant series of analyses and concluded in 1986, together with and independently of Robert Furchgott, that EDRF was identical to NO. The problem was solved and Furchgott's endothelial factor identified.
When Furchgott and Ignarro presented their conclusions at a conference in July, 1986, it elicited an avalanche of research activities in many different laboratories around the world. This was the first discovery that a gas can act as a signal molecule in the organism.