APEX1 and breast carcinoma: The genotype distribution in the ER+ (n = 55) and ER− (n = 45) was independently compared with the genotypes in the control samples (n = 100) (Table 4). APE1 variant rs1130409 showed higher risk in both ER+ and ER− breast cancer patients for Glu/Glu genotype and Glu alleles (Table 4).