HTR1F encodes a G-protein coupled receptor for serotonin (5-hydroxytryptamine) that mediates inhibitory neurotransmission 1. The receptor is coupled to G(i)/G(o) alpha proteins and suppresses adenylate cyclase activity upon ligand binding 1. HTR1F also functions as a receptor for lasmiditan, a clinically approved migraine therapeutic 1, and exhibits high conservation across vertebrate species 2. Beyond canonical serotonin signaling, HTR1F activation stimulates MAPK/ERK signaling cascades 2. Genetically, HTR1F variants contribute to migraine susceptibility as identified in a genome-wide association study of 102,084 cases, representing a novel migraine-specific drug target 3. HTR1F is also genetically associated with sleep apnea risk in non-obese individuals, with expression predominantly in neurons 4. Additionally, HTR1F expression correlates with ACTH release and potentially modulates pain-itch sensory processing in dorsal root ganglion neurons 56. Recent cancer research indicates HTR1F upregulation in 17 cancer types associates with poor prognosis and immune microenvironment alterations, particularly in lung squamous cell carcinoma 7. These findings establish HTR1F as a multifunctional receptor with relevance across neurological, sleep, and malignant disease contexts.