Ramaswami: One of the important cells of the immune system are the T cells. They are also known as the killer cells, due to their ability to destroy cells that are infected as well as cancerous cells. How exactly the T cells perform their aggressive tasks of destroying the diseased cells, still remains a question to ponder upon. One of the mechanisms, as revealed in a latest study says that the T cells have proteins inside them that are packed with deadly chemicals which unleash an attack on the target cells. The research was published recently in Science.