ACE2 and heart failure: For example, in a study, the ACE2 deletion mice exhibited myocardial hypertrophy and interstitial fibrosis, as well as exacerbated cardiac failure [57]. The pathogenesis in mice infected with influenza virus H5N1 was significantly aggravated by ACE2 deficiency, while the severity of lung injury was alleviated by the inhibition of AT1R [58].