The concordance of the KRAS mutational status (positive/negative) between DF and plasma was 72.2% (13/18): in 12 subjects (1 PDAC patient, 1 CCA patient, 2 IPMN patients, 2 pancreatitis patients, and 6 controls), the KRAS mutation was not detected in the cfDNA from either the DF or plasma, while in 1 control subject, the KRAS mutation was detected in both biological sources. The gene discussed is KRAS; the disease is cholangiocarcinoma.