Tumour biomarkers and an understanding of the mechanisms of epigenetic regulation are a key to identify novel epigenetic therapies, and epigenetic biomarkers also have potential to impact on clinical management in gynaecological cancer. DNA methylation has many potential advantages as a cancer biomarker since it is stable, provides a binary read-out and is frequently aberrant in cancer. Methylation profiling of tumours has allowed the identification of genome-wide DNA methylation patterns as well as the identification of loci that are associated with response or survival of women with ovarian cancer following chemotherapy. EZH2 knockdown in ovarian cell lines has been shown to lead to reduced cell growth/proliferation, as well as cell migration and/or invasion in vitro. It has also led to the re-sensitisation of drug-resistant ovarian cancer cells to cisplatin. Histone deacetylase (HDAC) and DNA methyltransferases (DNMT) inhibitors are now used in the treatment of certain haematological malignancies.