SP regulates a variety of physiological and pathological processes such as pain, gastric motility, inflammation, immunomodulation, emesis, and depression.[4] The biological responses to SP are mediated by the neurokinin receptors (NKRs), members of the G‐protein‐coupled receptor family, including NK‐1R, NK‐2R, and NK‐3R, of which NK‐1R confers the highest affinity to SP.[4] NK‐1R antagonists have been used clinically for the treatment of nausea and vomiting caused by cancer chemotherapy.[5]. The gene discussed is TACR1; the disease is major depressive disorder.