However, HIV-1 infection is lifelong, due in equal parts to the virus’s ability to integrate its genome into the chromosomal DNA of long-lived CD4+ memory T cells where it can reside undetected, while simultaneously evading the adaptive response during active replication by mutating its genome at a phenomenal rate [4 × 10–3 per base per cell, the highest for any described biological entity (Cuevas et al., 2015)]. This evidence concerns the gene CD4 and HIV-1 infection.