The stimulatory effects of HIV-1 gp120 may enable the direct infection of resting T-cells by activating calcium flux and NFAT signalling down the CCR5 signalling pathway, as well as upregulating inositol triphosphate-mediated signalling and the expression of the IL-2 receptor (Cicala et al., 2006; Kornfeld et al., 1988; Weissman et al., 1997). This evidence concerns the gene ITIH4 and infection.