Several studies have shown that levels of KRAS mutation in cfDNA correlated with radiographic tumor response to therapy in patients with mPDAC and predicted early recurrence following curative-intent resection.88 A recent study of 512 patients with PDAC found that ctDNA KRAS mutations were detected in 57% of patients, and the frequency of KRAS mutation differed depending on the metastatic organ. The gene discussed is KRAS; the disease is neoplasm.