HDAC9 and ovarian carcinoma: Although there is no definitive evidence linking histone modifications to the process of EMs malignant transformation, intriguingly, inhibition of the methyltransferase Enhancer Of Zeste 2 Polycomb Repressive Complex 2 Subunit(EZH2) and the acetyltransferase Histone Deacetylase (HDAC), which regulate histone modifications, can lead to tumor regression in ovarian cancer mouse models with ARID1A mutations (52).