This volume provides a comprehensive account of the most recent trends in human leukemia, as presented at the Ninth Wilsede Meeting. The internationally renowned contributors deal with all different aspects of these diseases: As well as discussing important clinical aspects of leukemia, new information on the biological basis of leukemia gained using the methods of molecular genetics, cell and molecular biology, virology, and immunology is covered. The book shows both the complexity of leukemia research, as well as the value of basic scientific research in furthering clinical medicine and therapy.

You see things, and sa)' why? But I dream 1hings that never were, and I say, 11'hy 110t? George Bernhard Shaw Far ahead of his time, June 1st, 1909, Alexander Maximov communicated in a lecture, given in the Charite in Berlin, the fundamental knowledge, that there exists a lymphoid hemopoetic stem cell. Alexander Friedenstein explained that during the following years, Maximov also showed that the idea of interaction between hemopoetic cells and their stroma to be one of the most significant experiences. Monoclonal antibodies, recombinant DNA technics and the improvement of tissue culture models are the major developments to improve our possibilities to clarify growth and differentiation functions of hemopoetic cells. During the last two decades it was shown that soluble products, released from T cells, were not only involved in inducing B cells to produce specific immunoglobulin secretion after antigen stimulation. Furthermore, lymphokines together with other cytokines regulate the growth and differentiation of hemopoetic cells. As I have learned from Dick Gershon, our knowledge of the cellular basis for immunoregulation has come a long way since 450 B.C. Thucydides comments on the possible role of immune response in controlling the Black Death. Dick Gershon speculated that no scientific interest for these interesting observations was put forth at that time. Perhaps the problems, the Athenians were having with the Spartans, converted money from basis research into the military budget.

Ideo autem omnes ad consilium vocari diximus, quia saepe iuniori Dominus revelat quod melius est. * Benedictus de Nursia Regula Benedicti, ca. 550 A. c. Caput III,3 The Wilsede Meetings were initiated in 1973 as an unusual experiment, and in the meantime this biennial symposium has already come to constitute an established and successful tradition. In June 1986 scientists and physicians met for the seventh time in the 3- year-old Emmenhof in Wilsede, in the heart of the Liineburg Heath, to dis- cuss modern trends in human leukemia. It was Pappenheim who in 1910 prepared the first international hematol- ogy congress. It was to have been held in Berlin under the title "Der groBe mononukleiire Leukozyt Ehrlichs, seine Morphologie und Funktion, seine Herkunft und seine Benennung" (Ehrlich's large mononuclear leukocyte. Its morphology, function, origin, and name), which was the most important and topical question at that time. It is amazing to think that as early as 1900, thanks to the pioneering research of Maximov and the innovative staining method developed by Ehrlich, the differentiation of the blood cells had, to a large extent, already been discovered. It is a sad fact that this congress never took place due to personal controversies among leading hematol- ogists, especially between Pappenheim and the Austrian hematologist Tiirk. Fortunately the Wilsede Meetings have never incurred this type of per- sonal controversies. On the contrary, both matter-of-fact discussions at a high scientific level and the development of personal friendships have always characterized their singular atmosphere.

In June 1984 a total of 169 physicians, scientists and students assembled in the now familiar and much-loved lair in the Wilsede Luneberg Heath near Hamburg, Germany, for the sixth biennial conference on Modern Trends in Human Leukaemia. This meeting, conducted by Prof. Rolf Neth in his own inimitable style, has established itself as one ofthe major events in the all too crowded programme of international conferences on leukaemia, cancer and related topics. Some may ponder why, with its "rustic" setting - flies, equine deposits, and lack of easy exit -, Wilsede has such an irresistible and persistent lure for so many of the world's top practitioners ofleukaemia research? The an- swer is, I suspect, a cocktail of Rolfs extraordinary charm, the pleasure of meeting friends and colleagues in a uniquely informal and relaxed atmo- sphere and the special style of the proceedings themselves, which focus on the evaluation of ideas and hypotheses rather than the cataloguing of data.