In 1989, the First International Symposium on Cytokines in Hemopoiesis, Oncology, and AIDS was held in Hanover, FRG. Since then there has been an explosion of knowledge in this field. New cytokines have been discovered, on which data are presented in this book, and receptors have already been cloned for many cytokines. In clinical application, some cytokines such as TNF have almost completely left the stage, but this may not be for ever. Enormous progress has been made in the field of hemopoietic growth factors, for which clinical studies from phase I to phase III have been conducted, and some of which have even been registered for routine use. In spite of this rapid development our knowledge of how to clinically exploit the effects of cytokines is very limited and lies far behind the advances made in basic research. Even for the hemopoietic growth factors, questions regarding the effect of adjuvant therapy on survival and or on general outcome in chemother apy have still not been answered. Discussion and exchange between those involved in basic science and clinical research is still urgently needed. We hope to successfully contribute to this process by continuing the series proceedings of the International Symposia on Cytokines in Hemopoiesis, Oncology, and AIDS. Hannover, in July 1992 Mathias Freund Hartmut Link Reinhold E. Schmidt Karl Welte List of Contributors Abbadessa, V. Istituto die Clinica Medica III, Centro Interdipartimenta de Ii Ricerche in Oncologia Clinica, 90100 Palermo, Italy Abecassis, M."