Caspase function and the immune system.

Caspases are key effector components of apoptosis, the process of programmed cell death. However, a large body of recent work has shown that caspase activity is necessary for several nonapoptotic cellular functions, such as proliferation, differentiation, survival, and the regulation of cytokine expression. In this review, we concentrate on the nonapoptotic functions of caspases and, in particular, on nonapoptotic roles of caspases in the immune system. Because of the involvement of caspases in promoting cell death, as well as cell proliferation and other nonapoptotic functions, studies involving the inhibition of caspases in vivo must be interpreted with caution.