In contrast to GIP, with pharmacological amounts of GLP-1, it is possible to restore beta cell responsiveness to glucose in T2DM patients, and this is currently being exploited in the new therapeutic agents developed on the basis of GLP-1 (exenatide[92],[93],[95] and liraglutide[98]–[100],[102],[227]). This evidence concerns the gene GCG and type 2 diabetes mellitus.