,4 Unfortunately, other cases of allogeneic stem cell transplantation have led to viral rebound5, 6, 7 and/or the emergence of rare pre-existing C-X-C chemokine receptor type 4, or CXCR4 variants,8 suggesting that novel strategies are needed to achieve a functional cure for HIV-1 infection. The gene discussed is CXCR4; the disease is HIV-1 infection.