MMP9 and neoplasm: Matrix metalloproteinase (MMP) played an important role in degradation of extracellular matrix and basement membranes, and previous studies indicated that the overexpression of matrix metallopeptidase 9 (MMP9) was associated with deep tumor invasion, lymph‐node metastasis, and advanced TNM stage in CRC (Lee et al., 2014; Matsuyama et al., 2002).