I remember, one day in 1990, a urologist friend of mine at UCLA asked me if I knew what the neurotransmitter was that stimulated erectile function. Okay. So every nerve releases a chemical, and that chemical stimulates something on the other side to produce an effect, a response. So there are nerves that go to the erectile tissue, both men and women. But the neurotransmitter, the chemical that incites that action, was not known. That’s why in 1990, for example, there were no drugs available whatsoever to treat erectile dysfunction. So when he asked me what the neurotransmitter was, I said, “You know what? I don’t know, but you’re the urologist. You should know. You tell me what it is.” And he said it’s not known. He asked me if it was possible to be nitric oxide. And I remember telling him, “Nah, it’s impossible. Nitric oxide is a gas. There’s no evidence that any neurotransmitter could ever be a gas,” and I let it go. Then I caught myself a few days later thinking inside the box. And I thought it was important to think outside the box. That’s what I had done before to show that nitric oxide was made by our arteries. So I thought about what he said, and I went and I read all about neurotransmitters, and believe me, there was no evidence that a gas could ever be a neurotransmitter. So despite all that, I said, “We’re going to do the experiments anyway.” So I went back to my urologist friend, who gave us samples of erectile tissue from humans and animals, and we did the experiments. And within a couple of months we found that the neurotransmitter was nitric oxide, and we published that. I remember the study on humans was published in 1992, and that stimulated a lot of attention. I was conducting interviews for two days from every newspaper and magazine and TV station you can think of, because it was obvious that was an important finding, because the major question was “Okay, now that we know what the neurotransmitter is, could this lead to orally useful drugs to treat erectile dysfunction?” And at the time, my answer was, “No, probably not, but hopefully it will.”