Interleukin 13 receptor, alpha 1 encoded by gene 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. This subunit serves as a primary IL13-binding subunit of the IL13 receptor, and may also be a component of IL4 receptors. Together with IL4R-alpha it can form a functional receptor for IL13. IL13Ra1 also serves as an alternate accessory protein to the common cytokine receptor gamma chain for IL4 signaling.