iNOS: inducible nitric oxide synthase; HTN: hypertension; I/R: ischemia/reperfusion injury; HW/BW: heart weight/body weight; HFrEF: heart failure with reduced ejection fraction; Bcl 2: B-cell lymphoma 2; ANG-II: angiotensin-II; WT: wild type. Here, NOS2 is linked to heart failure.