In the detection of pancreatic ductal adenocarcinoma, blood tests to detect mutations in ctDNA, specifically in the KRAS gene, have been combined with protein biomarkers that include carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9) and cancer antigen 125 (CA125) [40]. This evidence concerns the gene MUC16 and pancreatic ductal adenocarcinoma.