CD4 and cytomegalovirus infection: In that regard, here, we study the effect of CMV latent infection and age on the expression of CD161 and CD300a receptors on CD4+, CD8+, CD8+CD56+ (NKT-like), and CD4−CD8− (DN) T-cell subsets and their relation with the polyfunctionality marker CD57, which is a hallmark of CMV infection and aging in T-cells (37, 38).