N number, ACEI angiotensin-converting enzyme inhibitor, ARB angiotensin-2 receptor blocker, HTN hypertension, DM diabetes mellitus, IHD ischemic heart disease/coronary artery disease, CCF congestive cardiac failure, COPD chronic obstructive pulmonary disease, CKD chronic kidney disease. The gene discussed is ACE; the disease is chronic obstructive pulmonary disease.