BMI1 and cardiac hypertrophy: After Ang II treatment, Bmi‐1–/– mice showed more serious cardiac hypertrophy than WT littermates as evidenced by decreased LVEF and LVFS analysed by colour Doppler echocardiography, increased HW/BW ratios and aggravated hypertrophic features and myocardial fibrosis by H&E, WGA and Masson's staining (Figure 3).