SIX1 and breast cancer: Morphological assay showed that overexpression of SIX‐1 lead to disorganization of the epithelial morphology of MCF7 cells, leading to a fibroblast‐like morphology transition, whereas down‐regulation of SIX‐1 leads to reverse process (Figure 3A,B), indicating that SIX‐1 may contribute to EMT in BC.