GBP4 and oropharynx squamous cell carcinoma: The main objective of this study was to determine the difference in the methylation status of the immune gene promoters EDARADD, GBP4, HAVCR2, HLA DPB1, IL12RB1, MARCO, and SIGLEC12 in healthy oral mucosa versus oral and oropharyngeal squamous cell carcinoma (OOSCC) tissue.