This invention relates to the diagnosis and treatment of cancerous diseases, particularly to the mediation of cytotoxicity of primary and metastatic human tumor cells; and most particularly to the use of an isolated monoclonal antibody or cancerous disease modifying antibodies (CDMAB) thereof, optionally in combination with one or more chemotherapeutic agents, as a means for initiating the cytotoxic response in such human tumors, e.g. any primary or metastatic tumor sites which arise from hepatocytes. The invention further relates to binding assays which utilize the CDMAB of the instant invention.