MMP9 and neoplasm: In this study, we searched for associations among six genetic variants of MMPs (MMP1 rs1799750, MMP2 rs243865, MMP3 rs3025058, MMP7 rs11568818, MMP8 rs11225395, MMP9 rs3918242) and characteristics including patient age at diagnosis, tumor size (T), the status of lymph node involvement (N), the status of estrogen (ER), progesterone (PR), and human epidermal growth factor receptor 2 (HER2) receptors, tumor histological type (ductal, lobular, medullary, and other) and grade (G1–G2 and G3), progression, metastasis, and death (Table 2).