DR3 (Death Receptor 3) , officially named TNFRSF25 (TNF Receptor Superfamily Member 25), is also known as APO-3, TRAMP, LARD, and WSL-1. It is a death domain-containing receptor primarily expressed in lymphocyte-rich tissues such as spleen, thymus, and colon. Upon binding its ligand TL1A (TNFSF15), DR3 regulates both apoptosis and NF-κB signaling, playing a critical role in T-cell homeostasis and immune regulation. DR3 is implicated in autoimmune diseases including inflammatory bowel disease (IBD) and rheumatoid arthritis, and exhibits dual roles in cancer, acting as both a tumor suppressor and pro-metastatic factor depending on context. While no direct-targeting drugs are clinically approved, DR3 agonists are being explored preclinically for cancer immunotherapy, and the TL1A/DR3 axis remains an active therapeutic target for chronic inflammatory conditions.