In contrast, there is strong evidence for the CD25 expression and secretion in many malignant disorders and autoimmune diseases such as human-T cell lymphotropic virus-1(HTLV-1), B cell chronic lymphoblastic leukemia (CLL), acute lymphoblastic leukemia (ALL), hairy cell leukemia (HCL), Hodgkin lymphoma (HL), non-Hodgkin lymphoma (NHL), lung adenocarcinoma, head and neck cancers, as well as multiple sclerosis (MS), rheumatoid arthritis, and systemic lupus erythematosus. This evidence concerns the gene IL2RA and acute lymphoblastic leukemia.