The in vitro data indicated that the melanoma cell lines with suppression of IRF6 exhibited a methylation level >68.5%, while the in vivo data indicated that the highest value of such methylation levels among melanocytic nevus samples was 7.2%, and that the methylation levels of 21 clinical melanoma samples ranged from 0.0% to 65.4%. Here, IRF6 is linked to melanocytic nevus.