One of the main drivers of T2D improvement is the enhanced delivery of nutrients and bile to the distal gastrointestinal (GI) tract as a consequence of anatomical rearrangement, along with a rapid gastric emptying leading to increased nutrient-stimulated secretion of such gut hormones as glucagon-like peptide 1 (GLP-1), peptide YY and oxyntomodulin, implicated in the improvement of βcell function and food intake regulation (2) (3) (4). Here, GCG is linked to type 2 diabetes mellitus.