These include host restriction factors such as APOBEC3G [24–26], TRIM5α [27], Tetherin (also known as BST-2) [28, 29], SAMHD1 [30, 31], and MX2 [32–34], which have been reported to restrict HIV-1 infection and replication [35]. This evidence concerns the gene MX2 and HIV-1 infection.