The success rate for treatment of primary neoplasms has improved sig nificantly due to improved surgical, radiotherapy, and chemotherapy methods, and by supportive patient care. In contrast, the treatment of cancer metastases, the cause of most cancer deaths, has not been very successful. Approximately 50% or more of patients with primary malignant neoplasms already have established metastases. Consequently, the most important problem in cancer treatment is the destruction or prevention of metastases. Metastases research has obvious clinical importance. Yet it has only been recently that...