Persistent or chronic exalted levels of ROS inside a cell have been ascribed to disorders, inclusive of inflammatory or immune related or lung disorders, CLL-chronic lymphocyte leukemia, AML-acute myeloid leukemia [34], etc., also in these disorders, superoxide dismutase and erythrocyte catalase like enzymes are diminished. The gene discussed is CAT; the disease is B-cell chronic lymphocytic leukemia.