PRDM9 and cancer: For example, the CAF-secreted factor transforming growth factor-β,22, 50, 51 mediates epigenetic switches through SOX4 activation, which in turn modulates EZH2, a histone methyltransferase, in cancer cells.52 Furthermore, transforming growth factor-β treatments may induce genome-wide changes in DNA methylation, in liver cancer cell lines.53 Epigenetic players, such as miRNAs,54 also contribute to the maintenance of an invasive, cancer initiating cell phenotype.