Białkowska et al[39] reported that the polymorphism rs11568818 in MMP7 gene was also associated with a 2.39-fold increased prostate cancer risk in Poland, while Meng et al[40] also, compared the different effects of MMP polymorphisms in urinary cancer, they revealed that the rs3918241, rs2250889, rs17576, and rs17577 polymorphisms of MMP9 are not associated with altered risk of urinary cancer. Here, MMP9 is linked to prostate cancer.