A Briton man has become the second to be cured of HIV.Adam Castillejo is said to have tested negative 30 months after getting off anti-retroviral therapy. However, his doctors say what healed him was not the HIV drugs. Castillejo was being treated for cancer and had a stem-cell procedure. The Lancet HIV journal reported that donors of those stem cells have an uncommon gene that gives them protection against HIV. The BBC News further reported that in 2011, Berlin patient Timothy Brown was the first person reported 'cured' of HIV. Brown is also said to have undergone a stem cell procedure.