TNF and oral lichen planus: Although the etiology of OLP is still unclear, there is evidence that it is a complex immunologic disease mediated by cytotoxic cells directed against basilar keratinocytes and resulting in vacuolar degeneration and lyses of basal cells.1,3,4In OLP; local inflammatory response is increased because of continued production of cytokines, TNFα, GM-CSF, and IL-6.