CtDNA can be detected in blood serum or plasma, and the presence of tumor mutations in ctDNA is a poor prognostic factor in PDAC patients.10, –12 Moreover, increasing ctDNA levels over time and the detection of new mutations during chemotherapy are associated with progression of disease.13, –15 However, most studies focus on KRAS mutations only,13,15 while several other known cancer-associated gene mutations may indicate PDAC progression and treatment response as well. This evidence concerns the gene KRAS and cancer.