We report that the serine protease granzyme B (GrB), which is crucial for granule-mediated cell killing, initiates apoptosis in target cells by first maturing caspase-10. In addition, GrB has a limited capacity to mature other caspases and to cause cell death independently of the caspases. Compared with other members, GrB in vitro most efficiently processes caspase-7 and -10. In a human cell mo...
