IL4R stands for "Interleukin 4 Receptor" ). The IL4R gene is a protein-coding gene located on chromosome 16p12.1. It encodes the alpha chain of the interleukin-4 receptor, a type I transmembrane protein that can bind both the cytokine interleukin-4 and the cytokine interleukin-13 to regulate IgE production. Coupling to the receptor protein activates the JAK1/2/3-STAT6 signaling pathway.
Furthermore, IL4/IL13 responses are involved in the regulation of IgE production as well as chemokine and mucus production at sites of allergic inflammation. In certain cell types, they can signal by activating insulin receptor substrates, IRS1/IRS2. A soluble form of the encoded interleukin 4 receptor can be produced by proteolysis of the membrane-bound protein. This soluble form can inhibit IL4-mediated cell proliferation and IL5 upregulation by T cells.