Under these conditions, glucagon secretion at 2 mM glucose was reduced by 75% in hyperglycemic Fh1βKO mice compared with CTL mice, and, paradoxically, elevation of glucose stimulated rather than inhibited glucagon secretion, similar to the response of human islets from T2D patients at this high glucose concentration (Walker et al., 2011). This evidence concerns the gene GCG and type 2 diabetes mellitus.