PRDM9 and cancer: Among them, histone methyltransferase enhancer of zeste homolog 2 (EZH2) (Fig. 3g), the enzyme that catalyzes the tri-methylation of lysine 27 on histone H3 (H3K27me3), is a known, key epigenetic regulator and EMT inducer, which participates in the metastasis of a variety of cancers [34–37].