MMP9 and neoplasm: Among them, convincing evidence illustrated that the matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) are particularly effective in inducing decomposition of ECM and degrading collagen, fibronectin, and elastin which are closely related to metastasis and invasion of tumor cells, thereby facilitating migration and invasion in CRC progression (Gialeli et al., 2011).