CD4 and infection: Furthermore, as previously reported [7], a significant decrease in virus infectivity, evaluated in a single-round infection assay with non-replicative GFP reporter viruses, was observed when viruses were produced in UNG2- and RPA32-depleted HeLa-CD4 cells (Fig. 2d), suggesting that incorporation of UNG2 and RPA32 into viral particles is required for maintaining full HIV-1 infectivity in this single-round infection assay.