Fig. 2

The function of biological factors in the breast cancer brain metastasis. The induction of EMT in the breast cancer cells can enhance the metastasis into the brain tissue, since it is vital for the tumor cells to be separated from other parts of colony to enter into blood stream for reaching to the brain tissue. The exosomes are also critical regulators of breast cancer brain metastasis, since they can deliver bioactive molecules such as RNA, protein and lipid to affect the progression and metastasis of tumor cells. The non-coding RNAs are also regulators of breast cancer brain metastasis. In addition, the molecular pathways including STAT3, Notch, Wnt, PI3K/Akt/mTOR and ERBB, affecting breast cancer brain metastasis (Created by Biorender.com)