GCGR and type 2 diabetes mellitus: In any case, the clinical success of GLP-1-based drugs combined with agonism (e.g. tirzepatide [84]) or antagonism [100] at the GIP receptor, and of the even more advanced GIP/GLP-1/glucagon receptor triagonists [106], suggest that there is potential for further improvements in the effectiveness (for glycaemic control and weight reduction) of incretin-based medications for the treatment of type 2 diabetes, which might eventually challenge the role of bariatric surgery in inducing substantial weight reduction and type 2 diabetes remission.