G6PC1 and type 2 diabetes mellitus: In the fed-state, insulin exerts an inhibitory effect on hepatic glucose production mainly through downregulation of the key gluconeogenic gene G6Pase. In T2DM, insulin’s inhibitory effect on hepatic gluconeogenic enzymes is attenuated, which results in increased hepatic glucose output and fasting hyperglycaemia (Wilcox 2005).