The reduced ROS production found in the subjects with T2DM in this study after vitamin C supplementation and with down-regulation of miR-451a may be through CAB39/LKB1/AMPK signaling, as PI3K/AKT/mTOR signaling is the central pathway of glucose and lipid metabolism (Huang et al., 2018; Tuo & Xiang, 2018). Here, PIK3CA is linked to type 2 diabetes mellitus.