It has been known for over two decades that quiescent/resting CD4+ T-cells are highly refractory to HIV-1 infection[2,3], particularly to post-entry infection of R5-tropic, but not to X4-tropic viruses since resting CD4+ T-cells express the HIV-1 co-receptor CXCR4. The gene discussed is CD4; the disease is HIV-1 infection.