I should say immediately that this is an excellent book. For those interested in mucosal immunology, little more is necessary. It comprises an up to date and comprehensive series of 13 reviews by scientists who have made important contributions to the field. I am very pleased to have a copy; it will be extremely useful.

Clinical gastroenterologists spend a great deal of their time battling with mucosal T cells, yet because these cells are too small to be seen with an endoscope (in any case they would be obscured in exudate or by the epithelial cell layer) and are difficult to stain on formalin fixed histopathology sections, they are rarely observed. The weapons used against these adversaries are principally non-specific drugs which have, obviously, worked if the patient gets better.

Thus, although it is tempting to take Sherlock Holmes' attitude and, when told by Watson that the earth revolves around the sun, feel that the mind is an attic that when filled with details of astronomy (or mucosal immunology), will leave no space for the more useful minutiae of Egyptian tobacco (or the indications for the latest biliary expanding metal stent). But Holmes liked to have a comprehensive grasp of the background of the case, and I believe that he would not have missed a chance to study this book had he been a contemporary gastroenterologist.

The language of the book may be a problem for the non-immunologist, particularly if one's medical school notes stop at the Bursa of Fabricius. This is certainly state of the art immunology, but is directed at clinicians as well as scientists. Therefore, if you want to know more about current developments in inflammatory bowel disease, coeliac disease, or HIV, or you are just curious about what some of those cells that you see in biopsy samples might be doing, I strongly recommend that you invest some money in a copy of this book and some effort in reading it. Furthermore, I suggest beginning with the chapter on “Mouse models of gut inflammation”—such models may not be identical to human inflammatory bowel disease, but at least they give us an opportunity to understand it.

And if you can't remember what CD25 is? Get a copy ofImmunobiology by Janeway and Travers (3rd Edition; Current Biology Ltd, 1997); this is another excellent book where no previous knowledge is assumed. There you are—two rave reviews—or three if you count A Study in Scarlet.