An additional factor that may regulate HIV-1 infection in the first trimester is dNK secretion of IFN-γ and chemokines (CCL3 and CCL4), which inhibit HIV-1 infection of monocyte-derived dendritic and mononuclear cells, facilitated by cell-to-cell contact between dM and dNK cells to achieve optimal inhibition. This evidence concerns the gene CCL4 and HIV-1 infection.