Li X. et al. showed that miR-21 was significantly upregulated in diabetes mellitus, and miR-21 expression inhibits autophagy via the sprouty RTK Signaling Antagonist 1 (SPRY1)/extracellular regulated protein kinase (ERK)/mammalian target of rapamycin (mTOR) pathway for normal regulation of the heart [35] Inhibiting miR-21 expression in cardiomyocytes showed an increase in SPRY1 level while decreasing levels of p-ERK and p-mTOR. This evidence concerns the gene MTOR and diabetes mellitus.