OR5AN1 is an olfactory receptor that functions as a specialized detector of musk odorants, recognizing muscone, musk xylol, and musk ketone with nanomolar sensitivity 123. Upon odorant binding, OR5AN1 undergoes conformational changes that activate G-protein coupled signaling via the Gs class G-protein GNAL, triggering adenylyl cyclase activation and downstream olfactory signal transduction 4. Structurally, OR5AN1 stabilizes musk ligands through hydrogen bonding to Tyr260 in transmembrane helix 6 and hydrophobic interactions with aromatic residues, with hydrophobic interactions contributing 77% to binding affinity 4. OR5AN1 exhibits chiral selectivity, preferentially recognizing (R)-muscone over its S-enantiomer, and demonstrates broad responsiveness to diverse synthetic musks including nitromusks and macrocyclic ketones 43. Genetically, OR5AN1 variants influence individual differences in musk odor perception; the L289F allele increases receptor sensitivity, correlating with lower detection thresholds and greater perceived intensity in humans carrying this variant 5. Functionally, OR5AN1 can undergo allosteric modulation by α-β unsaturated aldehydes, which act as positive modulators and lower odor detection thresholds 6. OR5AN1 represents the dominant receptor for macrocyclic ketone musks and contributes significantly to human musk perception among a trilogy of musk receptors 7.