CCR5 and HIV infectious disease: The observation that homozygotes for the CCR5∆32 null mutation are highly resistant to HIV infection and that heterozygotes for this mutation progress more slowly to disease has led to targeted therapy in the form of approved CCR5 antagonists such as maraviroc, contributed to the only HIV cure in an adult recipient of a CCR5Δ32 allogeneic stem cell transplant (Hutter et al. 2009), and has been leading targets for genome-editing strategies in HIV (Tebas et al. 2014).