GZMB and neoplasm: The mechanism of emperitosis of immunotoxic cells is that after entering the tumour cells they are submerged in the tumour cell vesicles and further GzmB degranulation in the vesicles is re‐uptaken by the immunotoxic cells, triggering apoptotic signalling pathways within the immunotoxic cells not lysosomal‐mediated death.162, 163