TGFB1 and breast cancer: By using EMT‐related PCR array assay in MCF‐7‐SIX‐1‐OE and MDA‐MB‐231‐SIX‐1‐KD cells, we further found and confirmed that besides TGF‐β1, ZEB1 are also responsible for SIX‐1‐induced EMT in BC metastases (Figure 3).