To study the capability of TFPI-2 in suppression of the proliferation and invasiveness of breast cancer cells, we established three MDA231 cell lines: one was infected with a lentivirus vector expressing His-tagged human TFPI-2 (MDA231/TFPI-2), and the other two were TFPI-2 down-regulated cell clones using shRNA approaches (MDA231/Sh1 and MDA231/Sh2). The gene discussed is TFPI2; the disease is breast cancer.