a kind of cell helps destroy pathogens
genetically_engineered_viral_pathogen is genetically_engineered_pathogen. genetically_engineered_viral_pathogen is not genetically_engineered_pathogen. toxic_substance is not human_pathogen. pathogen is not microorganism. pathogen is microorganism. killer_t_cell is not t_cell. genetically_engineered_bacterial_pathogen is not genetically_engineered_pathogen. killer_t_cell is t_cell. pathogen is infectious_agent. toxic_substance is human_pathogen.