Among them is the gelatinase group (MMP2, MMP9), which selectively cleaves type IV basement membrane collagen, leading to the promotion of cell proliferation, invasion, and metastasis.46 The epigenetic regulation of MMP2 in OSCC, as shown in this and other studies, including DNA methylation at the promoter region and histone modifications, was shared with other cancers.52–54. Here, MMP9 is linked to cancer.