Therefore, we used a HPLC-MS/MS system for quantifying 5mC and 5hmC in genomic DNA from white blood cells (WBCs) in humans and rats and qPCR for detecting mRNA expression of SIRT6 and TETs to test the hypothesis that there might exist a link across SIRT6, TETs, and 5hmC in T2DM. Here, SIRT6 is linked to type 2 diabetes mellitus.