IL4 is a pleiotropic cytokine and a potent lymphoid cell growth factor that stimulates the growth and survivability of certain B cells and T cells. It is produced by activated T cells and is a ligand for interleukin 4 receptor. The interleukin 4 receptor also binds to IL13, which may contribute to many overlapping functions of this cytokine and IL13. STAT6, a signal transducer and activator of transcription, has been shown to play a central role in mediating the immune regulatory signal of this cytokine. Two alternatively spliced transcript variants of this gene encoding distinct isoforms have been reported. MW: 14 and 19 kDa, monomer. Purity ≥95%