HAVCR1 and Headache: This deletion disrupts a predicted enhancer (enh87362) in EnhancerDB34 that is predicted to regulate TIMD4. Notably, HAVCR1 is an important paralogue of TIMD4. As headaches and migraines are associated with changes in vascular blood flow to the brain, this deletion may contribute to the observed differences in headache incidence between Han and Tibetan individuals at high altitude41.