MMP9 and posterior cortical atrophy: Finally, the most important merit of our study was that this was the first study to examine the association of MMP1-1607 2G/1G, MMP2-1306 T/C, MMP2-735 T/C, MMP7-181 G/A and MMP9-1562 T/C polymorphisms with PCa risk using meta-analysis.