Interleukin-13 receptor subunit alpha-1(IL13RA1) is a subunit of the interleukin 13 receptor. This subunit forms a receptor complex with IL4 receptor alpha, a subunit shared by IL13 and IL4 receptors. The human IL13-Rα1 was originally cloned based on sequence homology to the mouse IL13-Rα1, it share 76% aa sequence identity. Human The IL13-Rα1 cDNA encodes a 427 amino acid (aa) residue precursor protein with a putative 21 aa residue signal peptide, a 324 aa residue extracellular domain, a 23 aa residue transmembrane region and a 59 aa residue cytoplasmic tail. The extracellular domain of IL13-Rα1 is also closely related to that of IL13-Rα2. It binds with low affinity to interleukin-13(IL13). IL13RA1 serves as a primary IL13- binding subunit of the IL13 receptor, and may also be a component of IL4 receptors. This protein has been shown to bind tyrosine kinase TYK2, and thus may mediate the signaling processes that lead to the activation of JAK1, STAT3 and STAT6 induced by IL13 and IL4.