Interleukin 13 Receptor alpha 1 (IL13RA1) is part of the interleukin 13 (IL-13) receptor complex expressed on the surface of various cells, including B cells, mononuclear phagocytes, dendritic cells, eosinophils, basophils, bronchial epithelial cells, and fibroblasts. The IL-13 receptor complex is composed of IL13RA1 and the IL-4 receptor alpha chain (IL4RA) and can bind both cytokines IL-4 and IL-13 with high affinity. Binding of IL-13 to IL13RA1 leads to activation of tyrosine kinase 2 (TYK2) and janus kinase 2 (JAK2), which phosphorylate the signal transducer and activator transcription 6 (STAT6), thereby inducing transcription of IL-13 responsive genes. IL-13 plays a crucial role in host defense against helminths and is involved in alternative macrophage activation to regulate inflammatory processes and to promote tissue repair and fibrosis. Moreover, IL-13 is associated with inflammatory diseases, such as asthma and allergic rhinitis, and promotes tumor cell proliferation and metastasis. It has been shown that expression of IL13RA1 is increased in inflammatory diseases and several types of cancer. Therefore, IL13RA1 represents a promising therapeutic target.
