MEF2D and breast cancer: Myocyte enhancer factor 2D(MEF2D) transduced multiple signals that activated ZEB1 expression and EMT, promoting metastasis in CRC.40 Polypyrimidine tract binding protein 3(PTBP3) promoted EMT in breast cancer by regulating the ZEB1 mRNA stability.41 GRHL2 protein was the first direct transcriptional repressor of the ZEB1 gene to be reported.25 In different biological backgrounds, the function of GRHL2 is not consistent, sometimes even completely opposite.