PCK1 and type 2 diabetes mellitus: There are two isoforms: the cytosolic isoform (PEPCK-C) encoded by Pck1 and the mitochondrial isoform (PEPCK-M) encoded by Pck2. Previous studies looking into PEPCK function focussed on the role of PEPCK-C in hepatic gluconeogenesis and its involvement in type-2 diabetes, due to its tight hormonal regulation4.