ATF3 and neoplasm: The tumor growth inhibition ratio calculated by tumor weight (values in brackets) for day 21 with the vehicle control group as a negative control were: vehicle control group, 0% (1.58±0.35 g); control-siRNA group, 8.9±2.3% (1.44±0.31 g); ATF3-siRNA group, 41.1±3.7% (0.93±0.22 g); cisplatin group, 54.4±4.5% (0.72±0.17 g); and ATF3-siRNA + cisplatin group, 75.3±5.5% (0.39±0.11 g).