Figure 4.Immunoheterogeneity of human plasma glucagon. (Copyright 1998 by Springer-Verlag. Reproduced with permission of Springer-Verlag from Gerich J and Cryer P. Counterregulatory hormones: molecular, biochemical, and physiologic aspects. In: Principles of Perinatal-Neonatal Metabolism. 2nd edition. Cowett R, ed. New York: Springer-Verlag, 1998, pp. 155-180.)