Here we investigated the effects of eight different stimulatory factors, including IL-2, IL-12, IL-15, IL-18, IL-21, cortisone acetate (CA), hydrocortisone (HC), and ascorbic acid (AA), on the ex vivo proliferation of 29 CAD patients’ NK cells, and correlated the results with the serum level of myocardial enzymes, including creatine kinase (CK), creatine kinase isoenzyme (CK-MB), and lactate dehydrogenase (LDH). The gene discussed is IL21; the disease is coronary artery disorder.