The aim of the present study was to compare for the first time the immunohistochemical expression of the immune response-related proteins GATA-binding protein 3 (GATA3), c-KIT/cluster of differentiation (CD)117, CD56 and CD45 between PVL, PVL-associated oral squamous cell carcinoma (OSCC) and solitary (localized) oral leukoplakia (OL) cases. This evidence concerns the gene PTPRC and oral cavity squamous cell carcinoma.