Qiao Xiaoying explored the role of renal cortex matrix metalloproteinase-9 in the clinical treatment of myocardial infarction and believed that renal cortex matrix metalloproteinase-9 is an important factor to promote the recovery of myocardial injury after acute myocardial infarction (Qiao et al., 2022). This evidence concerns the gene MMP9 and acute myocardial infarction.