For apoptosis-related proteins (41 proteins), IgG from ATLL donors strongly recognized cell cycle and apoptosis regulator 2 (CCAR2_frag), while HAM/TSP donors targeted cytokine-induced apoptosis inhibitor 1 (CIAPIN1) and caspase activity and apoptosis inhibitor 1 (CAAP1). The gene discussed is CAAP1; the disease is adult T-cell leukemia/lymphoma.