CD52 and acute lymphoblastic leukemia: While antibody-based immunotherapy for patients with T cell (T)-ALL is not yet established, some monoclonal antibodies against T cell expressed antigens such as C-C chemokine receptor type 4 (mogamulizumab), CD52 (alemtuzumab), and CD30 (brentuximab-vetodine) have been approved in the treatment of other indications and are currently evaluated preclinically and clinically also in T-ALL (4, 5).