The hybridoma technique for producing monoclonal antibodies, developed by Drs. Kohler and Millstein in 1975, revolutionized the field of tumor immunology. It is now clear that there are antigens associated with or restricted to human neoplasms that have biologic significance. Monoclonal antibodies have already been demonstrated to have great immunodiagnostic value and it is anticipated that they will become a component of our therapeutic armamentarium. Most investigators in the field, however, feel that the true potential of monoclonal antibodies in cancer therapy remains to be determined. Clearly the most encouraging results have been witnessed in the treatment of hematologic malignancies. This volume of CANCER TREATMENT AND RESEARCH explores the current state of the art of immunoconjugate therapy of hematologic malignancies. Immunoconjugate Therapy of Hematologic Malignancies provides an update of a rapidly advancing field. The preliminary experience of a number of investigators suggests a role for targeted therapy in the treatment of hematologic malignancies. At the present time, immunoconjugates have, in most instances, been reserved for patients with advanced refractory disease. However, it is anticipated in the future that these reagents will be utilized as a complement to traditional therapy or as post-remission consolidation in patients with minimal residual disease. The obstacles have been defined; solutions will require further research and creative imagination.