CCR7 is expressed in mature T-cell malignancies, such as adult T-cell leukemia/lymphoma (ATLL) [19] and Sézary syndrome (SS) [20], and enables the entry of acute lymphoblastic leukemia (ALL) cells to the central nervous system (CNS) where CCR7 promotes survival and proliferation [21, 22]. This evidence concerns the gene CCR7 and adult T-cell leukemia/lymphoma.