ELISA data revealed that IFN-γ protein expression levels were significantly decreased in the T lymphocytes of the non-erosive OLP group and the erosive OLP group (p < 0.05, n = 20), while IL-6 protein expression levels were greater than those in the normal group (p < 0.05, n = 20). The gene discussed is IFNG; the disease is oral lichen planus.