High glucose concentrations and glucokinase activators (GKAs) increase Ca 2+ signalling in β-cells, and increase intracellular Ca 2+ leads to activation of calcineurin and nuclear translocation of NFATc proteins. Indeed, concentrations of GNF4877 ((0.1 μM, 0.3 μM) well below the EC 50 for β-cell proliferation are able to induce proliferation in the presence of high glucose or pharmacological activators of glucokinase. Finally, increasing intracellular Ca 2+ with glibenclamide (a sulfonylurea receptor 1 inhibitor) or Bay K8644 (an L-type Ca 2+ sup> channel activator) show additive activity with GNF4877.