I am delighted to be able to write the foreword for this new book on Helicobacter pylori by three pioneers in the field, Vlf West­ blom, Steven Czinn and John Nedrud. Because of their long experience in both basic and clinical aspects of H. pylori, the editors have been able to produce a volume which is authoritative and up to date in the science of H. pylori, while still being concise and interesting for the practicing physician or H. pylori novice. To achieve this, they have collected a very distinguished group of authors from within the Vnited States and around the world. The chapters are sequenced in approximately the same order as developments in H. pylori science over the past 15 years. The first chapter on the discovery of H. pylori is by Cliodna McNulty, who was the first person to culture the organism in Europe. The epidemiology is then described followed by the main clinical as­ sociations, which are gastritis and dyspepsia, peptic ulcers, can­ cers and lymphoma. This naturally leads to discussion of the laboratory aspects of H. pylori, especially the microbiology, in­ cluding essential information on antibiotic resistance patterns. Next, virulence and pathogenicity of H. pylori are explained as defined in studies using animal models, then by discussion of the metabolism of the organism. Finally, the interaction of the bac­ terium with the host immune systems is dealt with, including the implications of these findings as they relate to the development of future vaccines.