FIS1 and type 2 diabetes mellitus: We found that T2DM upregulated the expression of CLOCK (Figure 3A,B) and downregulated the expression of OPA1 (Figure 5A,B) and Fis1 (Figure 5A,E) in the liver, and the expression of OPA1 and Fis1 were negatively correlated with the expression of CLOCK (Figure 6), suggesting that the regulation of the mitochondrial dynamics by CLOCK and BMAL1 may be opposite in the pathogenesis of T2DM.