CD40 is a protein expressed on the surface of B cells and a variety of tumor cells including human multiple myeloma. Since multiple myeloma is a universally fatal disease characterized by infiltration of malignant plasma cells in the bone marrow which migrate to the peripheral blood during advanced stages of the disease, understanding the mechanisms whereby CD40 regulates multiple myeloma cell growth and migration may both enhance our understanding of multiple myeloma progression and suggest novel therapies. This project will investigate CD40 activation mechanisms regulating multiple myeloma cell migration and identify new potential drug targets for the treatment of multiple myeloma and CD40-related diseases.