Dr. Li's major research focus is on the function of laminin extracellular matrix in epithelial malignancies including melanoma and squamous cell carcinoma. Basement membrane (BM) has traditionally been viewed as a barrier that cancer cells have to overcome to invade and metastasize. Recent studies have shown that cancer cells depend on their own array of BM molecules that they use as a substrate or track for their proliferation or invasion. The emerging view recognizes BM molecules in cancer as potential pro-tumorigenic autocrine factors. Tumor-derived BM molecules do not form morphologically BM ultrastructure found in normal tissues but form some important intermolecular BM associations that are crucial in supporting cancer cell function and tumor development. Laminins have been shown to be involved in a variety of critical processes including tumor cell attachment, migration and invasion. Dr. Li's laboratory is currently studying the functions of laminins (laminin-411 and laminin-511) in the processes of 1) tumor cell migration, invasion and metastasis, 2) tumor angiogenesis and microenvironmental regulation, and 3) interactions with cell surface integrin receptors and matrix metalloproteinases (MMPs), as well as potential application of laminin as a biomarker and therapeutic target.