There are numerous caveats that prevent this from becoming a surefire solution, though. Even if the CCR5 mutation wasn't extremely rare, you'd still have to match the immunological footprints of the donor and the patient to prevent the bone marrow from reacting badly to the recipient. Also, lead researcher Ravindra Gupta told Wired the transplant was a "last chance of survival" for a patient with Hodgkin's lymphoma. He needed both chemotherapy and the stem cells, the combination of which puts a lot of stress on your body. You likely wouldn't want to try this unless you'd exhausted other options.

Instead, you're more likely to see scientists focus on editing existing genes to disable CCR5 and prevent HIV from getting in. That's considerably harder and could bring controversy, but it would be less drastic and wouldn't require a highly unlikely donor match. In that light, the newly HIV-free patient is a sign that medical science is on the right track -- it's just going to take a while to reach the end of that track.