Higher bilirubin levels predicted by the UGT1A1 SNP were weakly inversely associated with risk of ovarian cancer overall and serous ovarian cancer with ORs per 1-SD increment equal to 0.96 (95% CI 0.92–1.00) and 0.94 (95% CI 0.90–0.98), respectively. The gene discussed is UGT1A1; the disease is ovarian serous adenocarcinoma.