As shown in Fig 2, exercise training elicited noteworthy reductions in DKK1 (baseline vs. after 12 weeks, mean ± SEM, 2571 ± 151 vs. 1716 ± 145 pg/ml, p = 0.002) and SFRP1 (880 ± 119 vs. 468 ± 75 pg/ml, p = 0.008) levels in the serum of breast cancer survivors, whereas no changes were detected in the control group (DKK1: 2613 ± 203 vs. 2365 ± 197 pg/ml, p = 0.08; SFRP1: 1,085 ± 149 vs. 1,039 ± 110 pg/ml, p = 0.35). This evidence concerns the gene DKK1 and breast cancer.