Finally, an estimation of the effect of TGF‐β expression on DFS of overall breast cancer patients by Kaplan–Meier method showed that a TGF‐β mRNA expression level over median level is significantly (p < 0.05) associated with more reduced DFS than the patients with lower level of TGF‐β (Figure 1D). This evidence concerns the gene TGFB1 and breast cancer.