The endothelin B receptor (ETBR), a G protein-coupled receptor encoded by the *EDNRB* gene, binds endothelin peptides (ET-1. ET-2. ET-3) and plays dual roles in physiological and pathological processes. Primarily expressed in endothelial cells, smooth muscle cells, neurons, and melanocytes, ETBR mediates vasodilation via nitric oxide and prostacyclin release, counterbalancing the vasoconstrictive effects of endothelin A receptor (ETAR). It also regulates cell proliferation, apoptosis, and ion transport. ETBR antibodies are critical tools for detecting receptor expression, localization, and activity in research. These antibodies (polyclonal or monoclonal) are widely used in techniques like Western blotting, immunohistochemistry, and flow cytometry to study ETBR's role in diseases. In cancer, ETBR overexpression correlates with tumor angiogenesis, metastasis, and immune evasion. In pulmonary hypertension, ETBR dysfunction contributes to vascular remodeling. Additionally, ETBR mutations are linked to Hirschsprung’s disease, a neurodevelopmental disorder. However, research findings can vary due to antibody specificity, tissue type, or disease context. Validated ETBR antibodies help clarify its signaling mechanisms, aiding drug development for endothelin-targeted therapies, such as receptor antagonists in cardiovascular and oncological research.