As expected, Kruskal–Wallis test and Dunn's test showed a significant difference in median serum levels of the more established PDAC biomarkers CA 19–9 and CEA between the group of metastatic disease and the post-resection levels after PDAC surgery (data not shown, p < 0.001 for both biomarkers). The gene discussed is CEACAM5; the disease is metastatic neoplasm.