TIMP3 and prostate cancer: While the transcriptional regulation of MMP genes by EZH2, which was out of scope of this study, is currently under investigation, our results support the possibility that overexpression of EZH2 in metastatic prostate cancer cells may elevate overall MMP activity both by decreasing the levels of TIMPs (TIMP2 and TIMP3) and by increasing the levels of some MMPs, such as MMP-9.