Nonetheless, it is known that some interleukins, saliva, and peripheral mononuclear cells in patients with including TNF-α, IFN-γ, IL-1, 2, 4, 5, 6, 8, 10, 12, 17, 18, 22, are involved in the pathogenesis of OLP [ 32- 33]. The gene discussed is IFNG; the disease is oral lichen planus.