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 (2 with smoldering type, 12 with chronic type, 14 with acute type, and 2 with lymphoma type) (Supplementary Table S1). Here, DPP4 is linked to adult T-cell leukemia/lymphoma.