Interleukin 17 receptor A (IL17RA) is also known as cluster of differentiation w217 (CDw217), is a pro-inflammatory cytokine secreted by activated T-lymphocytes, belong to ubiquitous type I membrane glycoprotein, and binds with low affinity to interleukin 17A (IL17A). IL 17R mRNA exhibits a broad tissue distribution, and has been detected in virtually all cells and tissues tested . IL 17RA associates with IL 17RC to form a signaling receptor complex for IL 17 and IL 17F . Ligand and IL 17RA ligation promotes T cell activation and the production of IL - 6, G-CSF, SCF, and multiple pro-inflammatory chemokines. Defects in IL17RA are the cause of familial candidiasis type 5 (CANDF5).