For example, Hata et al. reported that circulating tumor DNA detecting KRAS gene codon 12/13 mutations is an effective predictive marker for occult pancreatic cancer metastasis.16) In future, if the detection of micrometastasis in pancreatic cancer becomes feasible, strategies such as controlling micrometastasis before attempting resection could be considered, leading to further improvements in the prognosis of pancreatic cancer patients. This evidence concerns the gene KRAS and familial pancreatic carcinoma.