CCR4 and adult T-cell leukemia/lymphoma: Although HSCT and the anti-CCR4 therapy are widely tested, these modalities are used as a second-line treatment, and chemotherapy using antineoplastic agents still plays a major role and is the first line in the treatment of ATLL patients (Ishitsuka and Tamura 2014; Tsukasaki and Tobinai 2014; Utsunomiya et al. 2015).