Similarly, transforming growth factor (TGF)-β, an immune suppressing cytokine in the microenvironment of breast cancer, markedly reduces the expression of members of the miR200 family in breast cancer cells and thus relieves their suppression to ZEB1 and ZEB2, which underlies the mechanisms for TGF-β-induced EMT and tumor metastasis [15]. This evidence concerns the gene ZEB1 and breast cancer.