Based on our recent study that indicated a role for Stmn2 in regulating glucagon secretion by trafficking through the endolysosomal compartment in αTC1-6 cells,18 we were interested to determine if the diabetes-induced alterations in the levels of Stmn2 and glucagon in mouse islets were associated with changes in the pattern of intracellular trafficking through the endolysosomal system. This evidence concerns the gene GCG and diabetes mellitus.