The methylation status of the CpG dinucleotides in the ADHFE1 promoter was analyzed. A bisulfate-sequencing assay was performed using 1.0 mg of bisulfite-treated genomic DNA from the clinical samples. Bisulfite conversion was performed using the EpiTect Bisulfite Kit (QIAGEN, German) according to the manufacturer’s instructions. The fragments of interest were amplified using the following specific primer pairs designed with the MethPrimer software4 (link)7 (link): forward, 5′- GGAGATGGAGTGAAGGTTGTTT-3′; reverse, 5′- ATTAACTCAAAACCCCTCTCTCTC −3′. The PCR products were gel purified and cloned into the pMD19-T vectors using pMD19-T vector cloning kit (TAKARA, Japan). Individual bacterial colonies were picked and sequenced to analyze DNA methylation19 (link)