Interestingly, our study showed that fibroblasts derived from patients with breast cancer were more frequently of the 5A/5A genotype compared with normal fibroblasts and, together, this supports a previous study suggesting an association between the MMP-3 5A SNP and breast cancer susceptibility [27], although two subsequent studies failed to find such an association [28,29]. Here, MMP3 is linked to breast carcinoma.