NPY and neoplasm: Numerous data suggest that the targeting of the NPY/YR system with YR antagonists is a promising antitumor strategy and that these antagonists could be used as broad-spectrum antitumor drugs since NPY is involved in the proliferation (e.g., NPY promotes the growth of exocrine pancreatic carcinoma cells) [202], migration and invasion of tumor cells and in angiogenesis and because different tumors express YRs.