Expression of perforin and granzymes in vivo: potential diagnostic markers for activated cytotoxic cells.

Perforin and granzymes are considered to be instrumental in cell-mediated cytolysis by cytotoxic T cells and natural killer cells. Here, Gillian Griffiths and Christoph Mueller describe the expression of perforin and granzymes, emphasizing studies in vivo, and discuss the possibility that these proteins are useful diagnostic markers for immune responses involving cytolytic cells.