Details:
A series of molecular signals induced by granzymes which triggers the apoptotic death of a cell. The pathway starts with reception of a granzyme signal, and ends when the execution phase of apoptosis is triggered. Granzymes are serine proteases that are secreted by cytotoxic T cells and natural killer cells to induce apoptosis in target cells. [GOC:mtg_apoptosis, PMID:17158907]