When hair geneticist and dermatology professor Angela Christiano started losing her hair, she began to study the disease that was causing it: alopecia areata, which causes hair to fall out in round patches when the immune system attacks the hair follicles.

In a new study published in Nature, Christiano tested a drug known as a JAK inhibitor, which is already being used for other conditions, and successfully stopped hair loss in people with alopecia areata. There were only three participants in the study, but all of them saw their hair grow back after five months of treatment.

Christiano’s alopecia areata developed decades ago — and in the 1990s she sent photographs of her bald spots to Pakistani researchers, asking them to collaborate with her on a study about the disease. This collaboration is what ultimately identified the gene associated with alopecia areata. She has been studying the condition and attempted to find a cure for baldness for years — and in a previous study, she found a certain factor on follicle cells that attracts cytotoxic T lymphocytes, attacks foreign invaders (but in this case, the hair follicles).

The most recent study identified a receptor protein called JAK, which triggered the immune system to attack the hair follicles. JAK is linked to other diseases as well, so drugs already exist to inhibit the receptor protein — hence the JAK inhibitors (ruxolitinib and tofactinib) which stopped hair loss. After the researchers tested this in mice, they teamed up with the Department of Dermatology at Columbia University Medical Center to start a clinical trial in humans.

“The timeline of moving from genetic findings to positive results in a clinical trial in only four years is astoundingly fast and speaks to this team’s ability to perform translational science of the highest caliber,” Dr. David Bickers, Chair and Professor of Dermatology at CUMC said.

There are currently no FDA-approved treatments for alopecia areata. While the hair follicles remain alive and the person is otherwise healthy — and the hair often grows back — it can be a frustrating experience for someone to continually see their hair fall out in patches, grow back, then fall out again. Some treatments such as cortisone injections, topical minoxidil, and certain creams and ointments are out there — but Christiano and her team hope that they’ll be able to someday find a cure for baldness.