For example, a therapeutic antibody mogamulizumab (KW-0761) recently approved in Japan for treatment of ATLL [28], [29] is a humanized version of a murine MAb KM2160 which was established by immunizing mice with a peptide corresponding to N-terminal amino acid residues 2–29 of human CCR4 [30]. This evidence concerns the gene CCR4 and adult T-cell leukemia/lymphoma.