SOD2 and prostate cancer: Similarly, the Physician’s Health Study found that men in a broader population with the AA-SOD2 genotype randomly assigned to β-carotene (antioxidant) treatment (versus placebo) had a relative risk of 0.6 (95% CI, 0.2–0.9) for fatal prostate cancer, but found no significant association in men with the VV/VA genotypes [8].