This two-and-a-half-day symposium has concentrated on main aspects of the rapidly expanding field ofleukocyte markers in hematology. While leukemias are already being 'phenotyped' routinely in clinical centers, continued research on the developmental sta ge of cells and cell membranes, expanding into a malignant clone, permits new snap shots on hemopoietic differentiation. Thus the discovery of leukemia-associated anti gens, which so far have not been found on subpopulations of normal cells, has greatly stimulated the discussion on 'differentiation antigens versus tumor antigens'. The...

Much of the attention presently paid to leukemia is the result of recent progress in understanding and treatment. Chemotherapy of leukemia started in the late 1940s, and combination therapy evolved in the late 1950s. It was at that time that the clonality of leukemia was realized, after the discovery of chromosomal and then biochemical and immunological markers. And now we have the new data on retroviral and cellular oncogenes and the reports on human T -cell lymphoma/ leukemia viruses. Many more steps forward could be enumerated in a field which is so rapidly making the hematological...