A closer look
Bone marrow transplants don't just patch you up; they delete your factory settings and install a foreign biological operating system. When doctors treated Timothy Ray Brown for leukemia, they purposely sourced marrow from a donor with a rare CCR5-delta32 genetic mutation. As Brown’s body accepted the graft, his newly reconstituted immune system was biologically blind to HIV. He essentially became a human chimera, functionally curing himself of the virus as the new cells hunted down the old infection.
