Elevated expression of SP/NK-1R has been identified in multiple cancer types and promotes angiogenesis, proliferation, and metastasis of solid tumor cells, including breast (9, , , –13), gastric (14, 15), liver (16, –18), colon (19), and pancreatic (20, –22) cancer, as well as melanoma (23), in an autocrine, paracrine, or neurocrine manner. This evidence concerns the gene TACR1 and cancer.