In addition, GATA3 and STAT5 can regulate the expression of IL-2R and IL-4R to promote IL-4-GATA3 positive feedback.83 Multiple pathways, such as the Notch pathway and Wnt-β-Catenin pathway, may regulate the expression of GATA3 and Th2 differentiation.84,85 Th2 cells produce cytokines such as IL-4, IL-5, IL-13, IL-9, and IL-10, which can induce B cells to produce IgG1 and IgE, activate M2 macrophages, and recruit eosinophils.86 Th2 cells play roles in infection, helminth infection, and allergies and are also related to autoimmune diseases (Figure 2). Here, IL9 is linked to autoimmune disease.