MMP9 and head and neck squamous cell carcinoma: Through LASSO regression, 15 DEEGs (AGRN, EXPH5, CLIC4, TSPAN6, TGFBR3, FN1, MMP9, KRT13, THY1, HBA1, FCGBP, PFN2, BST2, EPCAM, and PIP) were identified as critical markers for predicting HNSCC development.