The functional IL4 receptor is formed by initial binding of IL4 to IL4R. Subsequent recruitment to the complex of the common gamma chain, in immune cells, creates a type I receptor and, in non-immune cells, of IL13RA1 forms a type II receptor. IL4R can also interact with the IL13/IL13RA1 complex to form a similar type II receptor. Interacts with PIK3C3 (By similarity). Interacts with the SH2-containing phosphatases, PTPN6/SHIP1, PTPN11/SHIP2 and INPP5D/SHIP (By similarity). Interacts with JAK1 through a Box 1-containing region. In Th1 cells, binds the N-terminal 50 amino acids of SOCS5, which inhibits JAK1 interaction, STAT6 activation and Th2 cell differentiation. SOCS5 interaction is independent of tyrosine phosphorylation.