MMP9 and breast cancer: Therefore, the present study has been performed to derive a more precise estimation of the association of MMPs and to elucidate the synergistic effect of genetic polymorphisms in the regulatory regions of MMP1 (rs1799750), MMP3 (rs35068180) and MMP9 (rs3918242) for susceptibility and progression of breast cancer by analysis of SNPs, haplotypes, LD, MDR, survival and in silico analysis along with epidemiological and clinicopathological variables in South Indian women.