– Tumor necrosis factor receptor superfamily member 27, also known as XEDAR and EDA2R, is a type III transmembrane protein of the TNFR superfamily. EDA2R consists of extracellular domain (ECD) with 3 cysteine-rich repeats and a single transmembrane domain but lacks an N-terminal signal peptide. EDA2R is widely expressed, notably in embryonic basal epidermal cells and maturing hair follicles. Even though it does not contain a cytoplasmic death domain, EDA2R can associate with Fas and induce EDA‑A2 dependent apoptosis. Its transcription is directly induced by p53, and it mediated cell death is p53 dependent. it is down‑regulated in breast, colon, and lung cancers, particularly in cases with p53 mutations. It also plays a role in EDA‑A2 induced skeletal muscle degeneration and osteoblast differentiation. Mutations in the EDA gene are associated with the X-linked form of Hypohidrotic Ectodermal Dysplasia (HED), a disease typically characterized by abnormal hair, teeth and sweat glands.