Moving away from anti-CD20 mAb, the anti-CCR4 mAb, mogamulizumab, is Food and Drug Administration (FDA) approved for use in adult T-cell leukemia/lymphoma (ATLL) as well as mycosis fungoids (MF) and Sézary syndrome, 2 subtypes of cutaneous T cell lymphoma (CTCL) [80]. This evidence concerns the gene CCR4 and adult T-cell leukemia/lymphoma.