The hallmark of an immune response is the generation of a large new cohort of specific lymphocytes dedicated to the removal of the stimulating antigen. The protection afforded by the mobilisation of an army of potentially destructive cells comes at a price as these cells, if uncontrolled, may turn on the host. Thus when excessive immune activity occurs, immunopathology resulting from the “friendly fire” of inflammatory cells may compromise healthy tissue. To safeguard against this, mechanisms have evolved that remove the expanded population of leucocytes both at the end of the immune response, when antigen is eradicated, and also when excessive activation may be taking place.1 The ligation of a surface membrane molecule CD95 (Fas/Apo-1) on activated T cells by its ligand leads to apoptosis.2 Although once activated, the expression of the CD95 receptor is …