INS and diabetes mellitus: In line with these observations, in C2C12 myotubes, insulin activated PDH and specific enzymes of the TCA cycle, which are controlled by insulin as suggested by their reduction in insulin-resistance, type 2 diabetes, and streptozotocin-induced diabetes: citrate synthase [43], aconitase [44], IDH [45], αKG dehydrogenase [46], and succinate dehydrogenase [47].