Targeting GCGR with antagonists, including small molecule inhibitors and monoclonal antibodies, has been suggested as a potential therapeutic strategy for managing both T1D and T2D.487–489 Several GCGR antagonists, such as MK-0893, MK-3577, LY2409021, and LGD-697, have been developed to enhance glucose tolerance, boost insulin secretion, and regulate blood glucose levels in animal models, demonstrating considerable efficacy in patients with T2D.490–493 GCGR monoclonal antibodies (mAbs) exhibit high specificity and strong targeting capabilities, making them relatively accessible. The gene discussed is GCGR; the disease is type 1 diabetes mellitus.