MBD2 and cancer: In terms of histone modification, a number of histone deacetylase inhibitors and demethylase inhibitors have been approved by the FDA as anti-cancer drugs.97, 98, 99 Recently, studies have shown that certain demethylase inhibitors and histone deacetylase inhibitors can suppress cccDNA transcription in tissue cultures without affecting host gene expression (Table 1).100