ACE and renal cell carcinoma: However, there were no significant differences in RCC risk among different classes of drugs when exclusive users of specific AHT medications were compared with beta blocker users, with risks of 1.2 (95% CI=0.4–3.3) for ACE inhibitors, 1.0 (95% CI=0.1–7.5) for angiotensin II antagonist, 0.9 (95% CI=0.4–1.9) for calcium antagonist, and 0.9 (95% CI=0.5–1.6) for diuretics.