leukemia is the production of the lymphocytes either B cell or T cells, B cells are more common as they are not as dangerous as T cell leukemias, Adult T cell leukemias are able to kill in the space of just a few months where as people can suffer from chronic lymphocytic leukemias (B cell) for years. It is a marked increase in lymphocytes, and are at most time anergic thus do not perform their immune role. There is a fault in the selection and survival signals which are received by lymphocytes during selection which inhibit the release of anergic and autoreactive lymphocytes