A recent meta-analysis reported dominant overexpression of IL-17 and Th17 cells in the local inflammatory infiltrates in oral lichen planus, predisposing inflammatory condition to OSCC, higher concentration of IL-17 in the serum of these patients, and more intense IL-17 expression in erosive than in reticular oral lichen planus, suggesting a positive correlation between IL-17 levels and disease severity [34]. This evidence concerns the gene IL17A and oral lichen planus.