DPP4 and adult T-cell leukemia/lymphoma: In this study, we investigated the expressions of CD39, CD73, and CD26 in leukemic cells (CD4+CD7−CADM1+ cells) and normal cells (CD4+CD7+CADM1−) from 40 patients, including 10 asymptomatic carriers of HTLV-1, and 30 ATLL patients.