PRDM9 and cancer: Histone deacetylases (HDACs), histone methyltransferases (HMTs) and the family of bromodomain and extra-terminal domain (BET) proteins, all three seem to be the most involved factors in the cancerogenesis process (230) involving epigenetic modifications, and as such, they are the target of cancer therapies: inhibitors of histone deacetylases (HDACi), histone methyltransferase inhibitors (HMTi), and histone reader protein inhibitors (bromodomain and extra-terminal domain proteins – BETi).