Viruses differently modulate the expression of DNAM-1 and their ligands depending on the infection phase. The viruses mentioned in this review (CMV, HIV-1, HSV, EBV, and HCV) differently express proteins associated with the various viral infection phases. Viral proteins (blue boxes) can upregulate (green arrow) or downregulate (red inhibition symbol) the expression of DNAM-1 and its ligands, such as PVR and Nectin-2, as reported in the legend. The US2 protein of CMV supports the immunomodulating function of UL141 during viral infection (blue arrow). References relative to each mechanism are reported in parenthesis. General missing information are indicated by emoticons, while missing information on viral molecules are indicated by question marks.