SERPINE1 and head and neck squamous cell carcinoma: In HPV-positive HNSCC, biomarkers such as Integrin alpha 5 (ITGA5), Transforming growth factor beta 1 (TGFB1), Plasminogen Activator, Urokinase (PLAU), and Plasminogen activator inhibitor-1 (SERPINE1) are associated with immune cell infiltration and increased radiosensitivity through NF-κB activation [26].