APP and head and neck squamous cell carcinoma: Results showed that 12 differentially expressed AGs (DKK1, SERPINE1, ADA, HMGA2, APP, CDKN2A, MIF, NEK6, ADM, BAK1, CDK6, and PRNP) were remarkably related to the OS of HNSCC patients (p < 0.05, Figure 2A).