Mutational analysis of the glucagon receptor: similarities with the Vasoactive Intestinal Peptide (VIP)/Pituitary Adenylate Cyclase-Activating Peptide (PACAP)/secretin receptors for recognition of the ligand’s third residue - Perret, J; Van Craenenbroeck, M; Langer, I; Vertongen, P; Gregoire, F; Robberecht, P; Waelbroeck, M (Biochem J, 2002)