HIV infection also tends to increase the production of T helper type-2 (Th2) cytokines (Interleukin-4 (IL-4), Interleukin-10 (IL-10)), proinflamatory cytokines (Interleukin-1 (IL-1), Interleukin-6 (IL-6), Interleukin-18 (IL-18)), and TNF-α; and it tends to decrease the level of T helper type-1 (Th1) cytokines, including Interleukin-2 (IL-2) and anti-viral interferon-gamma (IFN-α) [67]. This evidence concerns the gene IFNA1 and HIV infectious disease.