In this research project, we have so far obtained the following findings. 1) Lutheran (Lu), an immunoglobulin superfamily transmembrane receptor, is also known as basal cell adhesion molecule (B-CAM). Lu/B-CAM is a specific receptor for laminin α5, a subunit of laminin-511 (LM-511) that is a major component of basement membranes. In this study Lu/B-CAM was cleaved not only by MT1-MMP but also in a MMP-independent manner (Exp. Cell Res., 2014). In vitro studies also showed that the soluble Lu/B-CAM released from cell surfaces bound to LM-511. Moreover the soluble Lu/B-CAM influenced cell migration on LM-511. We further found that the released Lu/B-CAM was present in plasma of HCC patients. These results suggest that soluble Lu/B-CAM serves as not only a modulator in tumor progression but also a novel marker for HCC. 2) Lu/B-CAM binding phage antibodies were isolated from phage libraries derived from cancer patients. Of them, a phage clone exhibited the inhibitory effects on the Lu/-CAM binding to LM-511. The phage antibody against Lu/B-CAM may be useful for developing drugs to prevent tumor progression. 3) LM-511 stably anchors epithelial cells to basement membrane in vivo. Several studies have shown that LM-511 promotes not only cell adhesion but also tumor cell migration in vitro. In this study we found that a potent tumor promoter (TPA) altered cell adhesion to LM-511 through ROCK signaling pathway and promoted tumor cell migration on it (in revision). Our results suggest that cell migration on LM-511 requires the modulation of cell-attachment through the laminin receptors.