MMP9 and esophageal squamous cell carcinoma: Furthermore, upon AZD1775 treatment, the protein levels of MMP-2 and MMP-9, two critical enzymes involved in degrading the extracellular matrix, which play an important role in tumor-invasive and metastatic processes in various malignant cancers including ESCC (Li et al., 2009a; Chen and Pan, 2017), were greatly decreased (Figure 4D), Collectively, these data suggest that AZD1775 effectively inhibits the expression of MMP-2 and MMP-9 as well as the migration and invasion of ESCC cells.