By applying intraperitoneal injection of tamoxifen to induce Cre-LoxP mediated cardiac specific deletion of Aars2 for 5 d, we measured cardiac function by echocardiography (ECHO) at various time points and myocardial fibrosis by Masson staining at the experimental endpoint (Figure 1E). The gene discussed is AARS2; the disease is Myocardial fibrosis.