BMP2 and breast cancer: In addition, it was shown to favor lung metastasis in vivo, which was in agreement with several other recent studies.6,7,8 A possible interpretation to the dual roles of BMP-2 is that in the early stages of breast cancer development, BMP-2-induced apoptosis plays a dominant role owing to low number of tumor cells; as the tumor continues to develop, EMT and stemness induced by rhBMP-2 have more significant roles than programmed tumor cell deaths.