PRDX2 knockdown led to enhanced ROS generation in response to H2O2. SMMC-7721 cells were transfected with PRDX2 siRNA or non-targeting control siRNA; 72 h later, cells were treated with or without 300 µM H2O2 for 30 min. ROS generation was measured by incubating cells with carboxy-H2DCFDA simultaneously, followed by flow cytometry. M, mean fluorescence value; PRDX2, peroxiredoxin 2; siRNA, small interfering RNA ROS, reactive oxygen species.