KRAS and neoplasm: Fortunately, PDAC is rather unique, since in up to 90% of cases, the tumor carries activating mutations in the KRAS gene in the same hotspots (codons 12, 13, and 61), making cftDNA detection based on the presence of these mutations quite appealing for the purposes of liquid biopsy, mainly due to the fact that they can be analyzed not only by means of next-generation sequencing technologies, but also using cheaper targeted approaches such as polymerase chain reaction (PCR) [12].