OR1A2 is a G protein-coupled olfactory receptor primarily expressed on the plasma membrane 1, functioning as an odorant receptor with ligand-binding specificity centered on citronellic terpenoid structures 2. The receptor activates cAMP-dependent signaling cascades upon odorant binding, triggering transient intracellular calcium increases 13. OR1A2 recognizes diverse odorants including citronellal and citronellol, with distinct binding orientations defined by conserved amino acid residues in transmembrane domains 23. Beyond olfaction, OR1A2 exhibits ectopic expression in non-olfactory tissues, including alveolar macrophages and hepatocellular carcinoma cells, where ligand activation reduces proinflammatory cytokine release and phagocytic capacity 1, and suppresses hepatocellular carcinoma proliferation through p38 MAPK phosphorylation 3. Genetically, OR1A2 variants associate with neuroticism personality traits 4, and expression is downregulated in long-COVID-19 patients with chemosensory impairment, suggesting potential involvement in viral-induced sensory dysfunction 5. These findings position OR1A2 as a promising therapeutic target for steroid-resistant inflammatory lung diseases and hepatocellular carcinoma.