MMP9 and myocardial infarction: Additionally, higher levels of MMP-9 (Chen et al., 2020) and phosphatase and tensin homolog (PTEN) (Ling et al., 2020), as well as lower levels of Cx43 (Martins-Marques et al., 2020a) were identified in circulating EV from human MI patients, posing as promising circulating markers of disease.