After binding to the NK-1R receptor, also widely expressed in the body, the SP/NK-1R complex regulates many biological roles—physiological and pathological—implicated in neuronal survival and degeneration, in the regulation of the cardiovascular and arterial systems, in the regulation of respiratory mechanisms, in musculoskeletal and gastric motility, in sensory perception, in salivation, micturition, depression, pain, inflammation, and in cancer [14]. This evidence concerns the gene TACR1 and cancer.