MMP1 and cancer: Five SNPs, rs1799750 in MMP-1, rs243865 in MMP-2, rs11568818 in MMP-7, rs2252070 in MMP-13 and rs28366003 in MT2A has been studied in various cancers including breast [47–57], lung [47, 58–64] and colon cancer [44, 47, 65–75], but results were ambiguous.