FOXO1 and type 2 diabetes mellitus: One mechanism through which SIRT1 improves T2D symptoms is by deacetylating and thus activating FoxO1 in adipocytes and increasing FoxO1’s interaction with its coactivator CCAAT/enhancer-binding protein α (C/EBPα) to upregulate the transcription of the insulin-sensitizing hormone adiponectin (59).