Martine Rothblatt: So the 30,000-foot view that I realized from reading these articles in the case of my daughter is that the pulmonary artery, which is the artery that takes blood from the heart to the lungs, is different from every other artery in your body, which is kind of interesting.

The reason it’s different from every other artery in your body is arteries take blood from the heart, veins take blood to the heart. So all of the other arteries in your body take blood, which is full of red blood cells that have been freshly oxygenated. So when your heart pumps, all your body gets freshly oxygenated blood. So those arteries respond to the blood cells that have fresh oxygen.

Except the pulmonary arteries take blood from your heart, but it takes it to your lungs to get oxygenated. So those arteries are different. They are the only arteries in the body that carry de-oxygenated blood, blood full of the carbon dioxide that we get from our respiration cycle. So I said those arteries must be different, must be biochemically different than any other artery. And if I can find a molecule that will speak just to those arteries, I can open up those arteries and leave all the rest of the arteries alone.