CD4 and AIDS: Inasmuch as the HIV-AIDS research is in progress, we believe epigenetic immunity, similar to innate and adaptive immunity, is a heritable host immune response to the environment stimuli, specifically against the invasion of pathogenic nucleic acid to our DNA, embodying chromatin remodeling via DNA methylation, histone modification, and ncRNA function, which silences the expression of proviral HIV in a host memory CD4 T cell as well as in other immune cells that have genomic DNA.