WWOX and leukemia: As transcriptional silencing or downregulation of WWOX was found to be associated with aberrant DNA methylation and histone acetylation in two leukemia cell lines (Ishii et al, 2003), we examined several HCC cell lines expressing a very low level of WWOX mRNA after combined treatment with 5-aza-2′-deoxycytidine, inhibitor of DNA methyltransferase and trichostatin A, a histone deacetylase inhibitor.