In hepatocyte growth factor (HGF)-treated MCF-7 cells, Maroni et al. [54] demonstrated that the DNA binding of Ets1, activated by the MAPK/ERK1/2 transduction pathway, and the DNA binding of NF-kB played a critical role in CXCR4 transcription and protein induction and enhanced the invasion and migration ability of the breast cancer cells. This evidence concerns the gene MAPK3 and breast cancer.