This is an image of a group of killer T cells (green and red) surrounding a cancer cell (blue, center). When a killer T cell makes contact with a target cell, the killer cell attaches and spreads over the dangerous target. The killer cell then uses special chemicals housed in vesicles (red) to deliver the killing blow. This event has thus been nicknamed “the kiss of death”. After the target cell is killed, the killer T cells move on to find the next victim.