HF: heart failure; COPD: chronic obstructive pulmonary disease; RAAS: renin-angiotensin-aldosterone system; ACEi: angiotensin-converting enzyme inhibitor; ARB: angiotensin receptor blocker; LABA: long-acting beta2 agonist; LAMA: long-acting muscarinic agonist; NIV: non-invasive ventilation; ACPE: acute cardiogenic pulmonary edema; AECOPD: acute exacerbation of chronic obstructive pulmonary disease. The gene discussed is REN; the disease is chronic obstructive pulmonary disease.