Interestingly, when analyzing subjects diagnosed with heart failure with reduced ejection fraction (HFrEF) or with mid-range ejection fraction (HFmrEF), Conti et al. described a significant positive correlation between Sirtuin 1 (Sirt1) activity in peripheral blood mononuclear cells and both circulating ACE2 concentrations and the ejection fraction (EF). Here, ACE2 is linked to heart failure.