Based on a published article：Single-cell analysis reveals a stem-cell program in human metastatic breast cancer cells.  Nature,  2015 Oct 1; 526(7571):131-5.

   By using patient-derived-xenograft (PDX) mouse models, this study demonstrated that a proportion of human breast cancer cells could quickly shed from the breast cancer tissue engrafted in NOD/SCID (severe combined immune deficiency) mice, enter into the vascular system, migrate out, and form a secondary tumor in other organs. These high-metastatic cells are stem-like and resistant to chemotherapeutic drugs. While common chemotherapeutic drugs were able to kill the primary tumor cells, the stem-like high-metastatic cells survived. On the contrary, the anti-metastatic drug was ineffective at killing primary tumor cells. This finding indicated that survival mechanisms of the high-metastatic cells is different from that of the primary cells. Since tumors are composed of both primary tumor cells and high-metastatic stem-like cells, combinational use of anti-proliferation and anti-metastatic drugs are essential for better patient survival. While various anti-proliferation drugs are available in the anti-cancer drug market, there is a lack of anti-metastatic drugs. For this reason, our company focuses on developing anti-metastatic drugs through our self-invented screening platform which aims to improve the survival rate of cancer patients.