SLPI and head and neck cancer: As shown, NNMT, FLI1, SLPI, LAMP3, SERPINA1, GAS6, and CD274 have been often used as biomarkers for OSCC or head and neck cancer, while other genes listed have seldom been investigated in oral cancer and may be considered as novel biomarkers for OSCC prevalence and treatment (Supplementary Material, Table 1).