MxA has well-characterised antiviral activity against influenza A virus (Pavlovic et al., 1990), bunyaviruses (Kochs et al., 2002) and rhabdoviruses (Pavlovic et al., 1990), whereas closely related MxB has been shown to inhibit HIV-1 infection (Goujon et al., 2013; Kane et al., 2013; Liu et al., 2013) and more recently hepatitis C virus (Yi et al., 2019) and herpesviruses (Crameri et al., 2018; Schilling et al., 2018). This evidence concerns the gene MX2 and HIV-1 infection.