Xenopsin is a neurotensin-like octapeptide. XPF has antimicrobial activity. XPF is synthesized in the stomach and stored in a novel granular multinucleated cell in the gastric mucosa, it is stored as active, processed peptides in large granules within the granular gland secretions of the skin. Belongs to the gastrin/cholecystokinin family. Magainin subfamily.