CYP1B1 and cardiac hypertrophy: The 6β-OHT treatment brought back the effect of Ang II to cause aortic hypertrophy in Cyp1b1−/− and castrated Cyp1b1+/+ and Cyp1b1−/− mice as indicated by increased media to lumen ratio of the aorta (Fig. 3b and Fig. 4b, respectively).