Interestingly, while deletion of RANBP2-Cyp had marginal effects on infection by HIV-1G89V CA as expected, the ability of MX2 to enhance infection of this mutant was reduced in RANBP2∆Cyp cells (Fig. 2B), suggesting there may also be CA-independent effects of the Cyp domain on MX2 activity. This evidence concerns the gene PPIG and infection.