Background：Receptor for both interleukin 4 and interleukin 13. Couples to the JAK1/2/3-STAT6 pathway. The IL4 response is involved in promoting Th2 differentiation. The IL4/IL13 responses are involved in regulating IgE production and, chemokine and mucus production at sites of allergic inflammmation. In certain cell types, can signal through activation of insulin receptor substrates, IRS1/IRS2.Soluble IL4R （sIL4R） inhibits IL4-mediated cell proliferation and IL5 up-regulation by T-cells.
