RELT (RELT TNF receptor) is a member of the tumor necrosis factor receptor superfamily that plays critical roles in dental development, immune regulation, and cellular signaling. RELT is specifically expressed by secretory stage ameloblasts and odontoblasts during tooth development, where it is essential for proper enamel formation 1. Loss-of-function mutations in RELT cause autosomal recessive amelogenesis imperfecta type 3C, characterized by hypoplastic enamel with rapid attrition and altered mechanical properties at the dentino-enamel junction 12. Beyond dental development, RELT functions as an immune-regulatory molecule that may promote immunosuppressive environments in cancer contexts, with T cells from RELT-deficient mice showing increased anti-tumor responses and inflammatory cytokine production 3. RELT activates MAPK14/p38 and MAPK8/JNK signaling pathways and may play a role in apoptosis 4. In multiple myeloma, RELT promotes osteolytic bone lesions by enhancing osteoclast differentiation and maturation 5. RELT physically interacts with related family members RELL1 and RELL2, and all three proteins can be phosphorylated by OSR1 kinase 6. The protein has been strongly conserved across vertebrates, suggesting important physiological functions beyond tooth development 3.