Cytotoxic T lymphocytes (CTL) and natural killer (NK) cells are key immune effectors that eradicate infected cells and tumors. To destroy these targets, CTL and NK cells mostly use the granule exocytosis pathway which releases perforin and granzymes from cytolytic granules into the immunological synapse formed with the target. Granzyme B induces apoptosis through caspase-dependent and caspase-independent mechanisms. Granzyme is a serine protease that cleaves after aspartic acid residues and activates caspase-mediated apoptosis....