CDKN2A and oral lichen planus: Recently, the investigation of prognostic biomarkers in OLP and oral squamous cell carcinoma (OSCC) showed that p16[CDKN2A] methylation and miR-137 promoter methylation occur with a frequency of 25% and 35% respectively in patients with OLP, and 50% and 58.3% respectively, in patients with OSCC.