CD8+ cytotoxic T lymphocytes can kill host cells infected with various microorganisms and single individual cancer cells through direct cell-to-cell contact, but their ability to destroy a target of large mass remains unexplored. A study provided novel evidence on the capability of the immune system to eliminate large parasite-filled cysts associated with chronic Toxoplasma gondii infection by utilizing the aggressive invader activity of cytotoxic T cells. They may also prove effective for attacking solid cancers.