Restriction factors were first described as counteractors of HIV-1 infection and some well-characterized ones include APOBEC3G (apolipoprotein B mRNA-editing enzyme, catalytic subunit-like 3G), SAMHD1 (sterile alpha motif and histidine aspartate domain-containing protein 1), Tetherin/BST-2 (bone marrow stromal antigen 2) and TRIM5α (tripartite motif 5α) (80). This evidence concerns the gene BST2 and HIV-1 infection.