In contrast to dogs, in totally depancreatized humans, there is only a negligible amount of plasma glucagon, and in contrast to depancreatized dogs, in depancreatized humans, diabetes is very mild (Barns et al., 1977; Muller et al., 1979; Boden et al., 1980; Holst et al., 1983). Here, GCG is linked to diabetes mellitus.