Ability of the mammalian peptides, gastrin-releasing peptide (GRP) and neuromedin B NMB); the amphibian peptide, bombesin and the synthetic bombesin analogue, [D-Phe6, β-Ala11, Phe13, Nle14] bombesin 6−14 to interact with the three human classes of bombesin receptors. Data are partially from (Benya et al., 1995b; Ryan et al., 1998b).