Bombesin was first isolated from amphibian skin. It is homologous with gastrin releasing peptide (GRP) and has high affinity for GRP receptors. Bombesin is biologically active in the central nervous system. It suppresses feeding in rats and may play a role in fear and anxiety-related behavior. Bombesin and related peptides has been implicated in autoctrine simulation of cell proliferation in human small-cell lung cancer. Ladenheim, EE; et al., Endocrinology., 149, 971 (2008).