Th2 cells mainly induce humoral immune responses and produce Th2-type cytokines (IL-4, IL-5, IL-6, IL-9, IL-10, and IL-13) that increase the chances of survival of M. tb by decreasing the body’s anti-TB immunity and promoting M. tb immune escape and latent infection, mainly by suppressing Th1 immune responses and macrophage function [58]. This evidence concerns the gene IL9 and tuberculosis.