Although several ACE inhibitors and AT1R antagonists are used clinically for the prevention or reversal of pathological cardiac hypertrophy and subsequent heart failure, it remains to be investigated whether these beneficial effects are associated with elevations in the level of Ang (1-7) or activities of Mas receptors and AT2R. Because Ang II is known to produce oxidative stress, it has been suggested that the antihypertrophic effects of ACE inhibitors and AT1R blockers may be due to the antioxidant activities. This evidence concerns the gene AGTR1 and heart failure.