We have previously shown that in prostate cancer cell lines derived from advanced metastatic cancers, miR-31 is downregulated to contribute to the resistance to chemotherapy-induced apoptosis.22 Here, we demonstrated that mocetinostat activates the expression of miR-31, which in turn decreases the antiapoptotic protein E2F6. This evidence concerns the gene E2F6 and metastatic malignant neoplasm.