The CpG-islands with high frequency of methylation in CCA included 14–3–3σ, OPCML, SFRP1, HIC1, PTEN and DcR1 (81.4, 72.5, 63.7, 38.2, 35.3 and 28.4%, respectively). The gene discussed is PTEN; the disease is cholangiocarcinoma.