Anyone who came of age in the 1990s remembers the “Friends” episode where Phoebe and Rachel venture out to get tattoos. Spoiler alert: Rachel gets a tattoo and Phoebe ends up with a black ink dot because she couldn’t take the pain. This sitcom storyline is funny, but it also simply illustrates the question that I and many others in the field of “pain genetics” are trying to answer. What is it about Rachel that makes her different from Phoebe? And, more importantly, can we harness this difference to help the “Phoebes” of the world suffer less by making them more like the “Rachels”?