In the verification cohort, IgG autoantibodies against HSPA4, ENO1, PRDX6, PRPF19 and MMP14 were significantly increased in breast cancer patients with areas under the curve (AUCs) of 0.90, 0.89, 0.82, 0.78 and 0.77, respectively. This evidence concerns the gene PRDX6 and breast cancer.