TNF and oral lichen planus: The most studied inflammatory proteins are TNF-α [5, 14, 42, 141, 156–159], IL-1 [5, 14, 141, 160, 161], IL-6 [5, 14, 34, 42, 92, 141, 158, 159, 162–164], and IL-8 [2, 5, 14, 42, 141, 160, 161, 164] (NF-κB-dependent cytokines), which have been found to be increased in the saliva of patients with different OPMDs (including OLP, oral leukoplakia, verrucous proliferative leucoplakia, and oral submucous fibrosis) and OSCC in comparison to healthy controls.