We studied oral mucosa biopsies with epithelial dysplasia from 78 patients enrolled in a published 4-years' followup cohort, in which cancer risk for patients with p16 methylation-positive dysplasia was significantly higher than those without p16 methylation (by 150-bp MSP and bisulfite sequencing; +133 ~ +283, transcription starting site, +1). This evidence concerns the gene CDKN2A and dysplasia.