CYP1A1 and ovarian cancer: Also, four of the SNPs (rs4646903 and rs1048943 in CYP1A1, rs1056836 in CYP1B1, and rs743572 in CYP17), which were not statistically significantly associated with ovarian cancer and therefore not followed up by the OCAC, were associated with ∼10% increased or decreased risk of ovarian cancer per copy of the allele carried.