We previously encountered a case of early-stage PDAC in which KRAS mutations were detected in PJ within the resected PDAC tissue but not in the plasma, suggesting that PJ is superior to blood for PDAC diagnosis as it may reflect DNA mutations or abnormal RNA expression from the original tumor more precisely owing to the short distance between the primary lesion and the position from where PJ is collected [28]. Here, KRAS is linked to neoplasm.