KRAS and familial pancreatic carcinoma: This led to the hypothesis that free DNA is linked to the presence of tumors.13 In the period of scientific progress, CTC was initially isolated from blood in 1998 and was proven to correlate with pathologic staging, and it has only since been employed in the clinic.14 Additionally, in 1994, PCR was used to identify the first KRAS mutation in pancreatic cancer patients’ blood cfDNA, and the results were consistent with those found in tumor tissue.15 In 1996, Raposo provided evidence that EVs possess biological activity.