Uncoupling protein 2 (UCP2) expression has minimal effect on intracellular adenosine triphosphate (ATP) content (A), but slightly increases glutathione (GSH) contents (B) in transfected cells. From left to right: transfection with C-UCP2, N-UCP2, noncoding-UCP2, EGFP-C1 vector alone, and nontransfected Hepa 1–6 cells. (*) P<0.05 and represents statistical analysis versus noncoding and vector alone–transfected cells.