As previous publications observed an up-regulation of Pex2 at the mRNA level in hepatic carcinomas (Chen et al. 2002; Wurmbach et al. 2007), Cai and colleagues silenced Pex2 by RNAi in hepatocellular carcinoma xenografts and reported significantly reduced tumor growth in response to the treatment. The gene discussed is PEX2; the disease is neoplasm.