However, during the immune response in TB, IL-33 increases the number of Treg cells and stimulates the production of cytokines such as IL-4, IL-5, and IL-10, as well as the suppression of IFN-γ in polarized Th1 cells, which is permissive for the mycobacteria and detrimental to the host [63,64,65]. The gene discussed is IL4; the disease is tuberculosis.