CD4 Th cells include Th1, Th2, and Th17 cells. Th2 cells secrete IL-13, which can promote goblet cell proliferation through STAT6 signaling. Th2 cells can also secrete IL-4, IL-5, IL-9, and IL-25 to promote the metaplasia of ciliated cells and Clara cells into goblet cells. Th17-secreted IL-22 can regulate goblet cell differentiation and promote goblet cells in the case of intestinal inflammation. Other cytokines, such as IL-33 and SPDEF, can also affect goblet cells. IL-33 promotes the proliferation of goblet cells, and SPDEF regulates the maturation and differentiation of goblet cells.