Currently, OSCC commonly includes the following types of biomarkers: IHC markers, such as PD-L1 [103,104], p16 [105,106], EGFR [107]; serological markers, including Carcinoma-specific carcinoembryonic antigen (CEA) [108], CA-125 [109,110], CYFRA 21-1 [111]; salivary markers, such as IL-1β, IFN-γ, TNF-α, IL-6, IL-8 [112,113]. Here, CEACAM5 is linked to carcinoma.