TAS2R20 is a bitter taste receptor expressed on cell membranes that functions as a chemosensor for bitter compounds. In oral tissue, TAS2R20 mediates bitter taste perception of compounds like vanillin through gustducin-linked signaling 1. The receptor activates a canonical taste transduction pathway involving gustducin, phospholipase C-beta-2, and TRPM5 ion channel gating. Beyond taste buds, TAS2R20 is highly expressed in extraoral tissues including bronchial epithelium and airway smooth muscle 2, where it participates in chemosensory functions. In lung macrophages, TAS2R20 is expressed and upregulated by lipopolysaccharide stimulation, though specific TAS2R20 agonists show limited anti-inflammatory effects compared to other TAS2Rs 3. Disease relevance includes cardiovascular and metabolic pathways: a multi-ethnic association study identified TAS2R20 within a significantly enriched bitter taste perception pathway linked to carotid plaque burden 4, and intestinal TAS2R20 expression correlates with weight loss following bariatric surgery in women with metabolic syndrome 5. TAS2R20 expression is also altered in depression, with downregulation observed in unipolar depression 6. These findings suggest TAS2R20 functions beyond gustatory perception in metabolic, vascular, and immune regulation.