MAPK3 and Myocardial fibrosis: Diabetic cardiomyopathy (DCM) is a type of cardiomyopathy that occurs in the state of diabetes, that is, extensive focal necrosis of the myocardium on the basis of microvascular disease, and leads to subclinical cardiac dysfunction, and eventually progresses to arrhythmia, heart failure and cardiogenic shock, etc. Studies have shown that ERK1/2 plays a role in regulating myocardial oxidative stress, apoptosis, myocardial hypertrophy and myocardial fibrosis, and these processes are related to DCM (Xu et al., 2016).