On the heels of World AIDS Day comes a stunning medical breakthrough: Doctors believe an HIV-positive man who underwent a stem cell transplant has been cured as a result of the procedure.

Timothy Ray Brown, also known as the “Berlin Patient,” received the transplant in 2007 as part of a lengthy treatment course for leukemia. His doctors recently published a report in the journal Blood affirming that the results of extensive testing “strongly suggest that cure of HIV infection has been achieved.”

Brown’s case paves a path for constructing a permanent cure for HIV through genetically-engineered stem cells.