Transgenic and knockout models for studying diseases of the immune system.

The advance in transgenic animal technology, and in particular the use of germline manipulation for the creation of targeted gene mutations, has resulted in the generation of a plethora of murine models for the study of diseases of the immune system. In the past year, a number of studies have given us interesting, and sometimes unexpected, insights into the events that lead to immune dysregulation. Surprisingly, similar disease manifestations can arise in experimental animals with quite different immune abnormalities. This review is focussed on mice with mutations affecting T cells and T-cell function.