Rescue of CAN2 activity induced cell death in ATL cells. (A) Correlation between CAN2 and SPTA2 expression level in 27 cases. (B) Cell proliferation was measured by MTT assay on SO-4, KOB, and KK1 cells 36 hours after transfection of mock vector or Δ₁₉CAN2. *P < .05; **P < .01 by Student t test. (C) Overexpression of Δ₁₉CAN2 significantly accelerated cell death in 3 ATL (SO-4, KOB, and KK1) and 4 non-ATL (Jurkat, SUP-T1, CCRF-CEM, and MOLT-3) cell lines. **P < .05 by Student t test. The drastic attenuation of SPTA2 expression was observed after transfection of Δ₁₉CAN2 in SO-4 cells (D), but not in Jurkat cells (E). The immunoblot of anti-myc tag confirmed the expression of exogenous Δ₁₉CAN2.