Another study suggested that genetic variants in MMP2 (rs2285053), 7, 9, and TIMP2 genes are associated with higher susceptibility of gallbladder cancer.41 Functional polymorphisms in the promoter regions of MMP2 (−735 C > T) and MMP3 are not associated with melanoma progression.42 Zhou et al43 suggested that the genetic polymorphisms or haplotype in the MMP2 promoter (rs243865, −1306 and rs2285053, −735) might play a role in mediating the susceptibility to nasopharyngeal carcinoma in Chinese populations. Here, MMP3 is linked to gallbladder cancer.