Louis Ignarro: Others were doing work on nitric oxide — had just started to do work on nitric oxide — which is a very unstable poisonous gas in the earth’s atmosphere. So I was wondering, “Why are these people…” there were only two of them — “Why are they studying nitric oxide?” So I was following what they were doing, talking to them. And then I realize, “Oh, you know, maybe certain drugs that we take to treat disease may work through a nitric oxide mechanism.” And I was thinking of that. And then one day, while teaching the pharmacology of blood pressure-lowering drugs in class at Tulane Medical School, one of the medical students after my lecture asked me — I had just talked about nitroglycerine. Nitroglycerine is a drug. It comes as a little tablet which you put under your tongue if you feel that you’re having a heart attack, and it can actually save your life by preventing that heart attack, relieving chest pain. So this medical student asked me what was the mechanism of action of nitroglycerine. I had talked about what it does, but I did not talk about how it worked.