CpG methylation in the promoter region of CDKN2B was quantified using pyrosequencing. The EpiTect Bisulfite Kit (Qiagen, Hilden, Germany) was used for bisulfite conversion of genomic DNA; the PyroMark Gold Q96 Reagents (Qiagen) and the PyroMarkTM Q96 ID instrument (Biotage AB, Uppsala, Sweden) were used for pyrosequencing, according to the manufacturer's instructions. A total of seven CpG sites were analyzed per sample. The primers for the analysis of CDKN2B-specific CpG regions were the same as those used by our group in a previous study [20 (link)].