As a genetically controlled program, apoptosis has important roles in a variety of biological processes. The realization that chemotherapy can also induce apoptosis in some cancer cells both in vitro and in vivo indicates apoptosis may play a very important role in cancer and cancer therapy (1 ,2 ). Many of the molecules that participate in the apoptotic cell suicide have been identified. At the heart of this pathway are a family of cysteine proteases, the “caspases” (3 ).
