Cell host & microbe 22(5) 575-576 pii 10.1016/j.chom.2017.10.012
How can an innate immune sensor shape viral evolution? In recent work, Takata et al. (2017) determined that the antiviral protein ZAP recognizes CG dinucleotide composition to differentiate self from non-self. This pressure may have driven CG dinucleotide suppression in HIV-1 and other RNA viruses to evade host antiviral defenses.