HDAC9 and neoplasm: By treating NSCLC cell lines with low RhoB expression with the HDAC inhibitor, trichostatin (TSA), they showed a substantial gene reactivation in the cell lines, suggesting the epigenetic regulation of RhoB. As previously demonstrated [61], the context of RhoB expression may explain the apparent contradicting observations between these studies and the ones mentioned above supporting RhoB function as a tumor promoter.