Compared with the inhibition of CD4+ T cell proliferation with shifting from Th2 to Th1 in MLR of APS + CD4+CD25+Tregs + CD4+T cells (CD4+CD25+Tregs: CD4+T = 1∶100), anti-TLR4 + APS could markedly suppress CD4+ T cell proliferation and reverse CD4+ T cell differentiation in mixed lymphocyte reaction. Here, TLR4 is linked to autoimmune polyendocrinopathy.