MMP1 and breast carcinoma: High-risk and low-risk genotypic combinations were determined based on the threshold value, which was 1 (300/300) for the present data where the TT genotype of MMP9, 6A6A genotype of MMP3 and 2G2G genotype of MMP1 conferred a 3 fold high risk (8/2) for breast cancer as shown in Table 8 (S1 File).