HIV-1 infection also profoundly altered expression of the cell cycle and apoptosis regulatory genes including BAX, BCL2, CDKN1A, GADD45A, CDk9, IRF1, CEBPB, and IRF2. The changes in the expression levels of these genes were more pronounced in HD-HIV cells when compared to HUT78-HIV. This evidence concerns the gene GADD45A and HIV-1 infection.