In comparison between 30 Oral Lichen Planus (OLP) and Oral Lichenoid Reaction (OLR) patients, it was found that the degranulated mast cells, ratio of degranulated mast cells and TNF-α was foundto be elevated significantly in OLR than in OLP patients thus opening a potential of diagnostic marker to differentiate these entities [11]. This evidence concerns the gene TNF and oral lichen planus.