IFNB1 and HIV-1 infection: Given that HIV-1 infection induces type I interferon (IFN) production in in vitro cell cultures [44] and infected individuals during the acute phase [45], taken together with the fact that type I IFNs potently enhance the expression of APOBEC3 genes [42], [46], we further evaluated the expression level of IFNB, a type I IFN.