In addition, CD30L can be found in epithelial cells and Hassall’s corpuscles within the thymus medulla, as well as both protein and mRNA forms of CD30L that are expressed in malignant hematopoietic cells, such as chronic lymphocytic leukemia, follicular B-cell lymphoma, hairy cell leukemia, T-cell lymphoblastic lymphoma, and adult T-cell leukemia lymphoma. The gene discussed is TNFSF8; the disease is hairy cell leukemia.