Moreover, NPY, via Y1R/Y5R, promoted the death of tumor cells in Ewing sarcoma [10,138,139,140], but under hypoxia, NPY acted as a tumor growth-promoting agent because these conditions favored Y2R expression and the formation of NPY3-36 that served as a Y2R/Y5R agonist and favored the migration of tumor cells [10,140]. Here, NPY is linked to neoplasm.