In our study, Epigenetic regulation of RhoB expression was investigated by analyzing the effect of histone deacetylase (HDAC) inhibitor trichostatin (TSA) and methyltransferase inhibitor 5-Azacytidine (5-Aza) on ovarian cancer SKOV3 and A2780 cells via RT-PCR and western blot. This evidence concerns the gene HDAC9 and ovarian carcinoma.