Humoral immune responses against NY-ESO-1 are detected in a subset of patients with ATLL. Sera were collected from 43 primary ATLL patients, and antibody responses against 10 CT antigens (NY-ESO-1, MAGE-A1, MAGE-A3, MAGE-A4, MAGE-A10, CT-7, CT-10, SSX-1, SSX-2, and SSX-4) were analyzed by ELISA as described in “ELISA.” This experiment was performed at least twice with similar results.