Remodelling the H-2 map

Dabbling in the field of cell-mediated immune responses involves a considerable risk of stumbling over the major histocompatibility complex (MHC) if only because T cells have dual specificity for antigen and self-MHC molecules and because MHC molecules regulate T-cell responses. The amazing progress made by molecular biologists in examining the mouse MHC has led to the startling conclusion that more H-2 class-I genes have now been discovered by DNA technology than can be accounted for by immunologists, although admittedly some of these genes may behave as pseudogenes whose products are not expressed. The latest insights into the H-2 map were discussed at a recent meeting.