MMP9 and cancer: There were 17 articles including 1,218 metastasis-positive and 1,337 metastasis-negative cases for MMP1 (−1607) 1G/2G, 4 articles with 2,234 cancer cases for MMP2 (−1306) C/T, 8 articles with 2,367 cancer cases including 783 metastasis-positive and 1,584 metastasis-negative cases for MMP3 (−1171) 5A/6A, 3 articles with 808 cancer cases for MMP7 (−181) A/G and 10 articles involving 2,552 cancer cases (1,129 metastasis-positive and 1,423 metastasis-negative cases) for MMP9 (−1562) C/T.