REN and Familial prostate cancer: We found that the use of agents acting on the renin-angiotensin system was associated with reduced risk of prostate cancer (odds ratio (OR) = 0.42; 95% confidence interval (CI) = 0.27–0.63, P < 0.001), and there was a nonlinear association of ‘decrease-to-increase-to-decrease’ (P < 0.0001).