To further investigate the effects of ATP11b and Ptdss2 on tumor metastasis, we used 628-GFP cells, in which a metastatic GFP signal could be detected in the lung 4 weeks after orthotopic injection because 628 cells have a significantly higher PS population on the cell membrane than 545 cells, as revealed by FACS analysis (Figure 6, C and D), and lower ATP11B protein levels than 545 cells, as determined by Western blotting (Figure 6, E and F). This evidence concerns the gene ATP11B and neoplasm.