introduction: bombesin is a 14-aminoacid peptide isolated from frog skin. the mammalian counterparts of the frog peptide are neuromedin b (nmb) and gastrin-releasing peptide (grp). bombesin (bbn) is a peptide showing high affinity for the gastrin releasing peptide receptor (grpr). prostate, small cell lung cancer, breast, gastric, and colon cancers are known to over express receptors to bombesi...