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). This evidence concerns the gene HDAC9 and ovarian cancer.