Current problems in research and treatment of leukemias as discussed at the symposium of the International Society of Haematology on leukemias in Dresden (Germany) are dealt with in detail in this volume. The characterization of leukemic cells and the evaluation of their function are themes, with the first hints emerging of the possibility of relating them to the intensity of treatment required. The cytokines, responsible for cooperation between cells, are also of great importance, and the beginnings of therapeutic applications can be discerned here. Not only are the cytokines themselves very interesting, but also the application of cells producing cytokines according to the range of macrophages found. The emphasis on cell-to-cell relationship is thus a main topic of the book. Of course, other treatment such as bone marrow transplantation and interferon therapy play an important part, too, and the latest results of chemotherapy are reported. A further essential area covered is the diagnosis and therapy of chronic leukemic diseases, the inclusion of which suitably rounds off the book. I am very grateful to the out­ standing specialists from both the West and the East who contributed to the symposium and this book: an important sign of collaboration and integration for the future.