CDKN1A and type 2 diabetes mellitus: Human T2DM case-control studies and intervention studies in non-diabetic people showed epigenetic alterations of PDX1, CDKN1A (cyclin-dependent kinase inhibitor 1; involved in cell cycle regulation) and GLRA1 (glycine receptor alpha 1; down-regulation of neuronal excitability) genes which seem to contribute to diabetes (6).