The results indicate that serum MIC-1 levels are higher in PDAC patients than in patients with any of the other tumors (p = 0.067 compared with colorectal adenocarcinoma, each P < 0.05 compared with other seven tumor group), which implies that high levels of MIC-1 may serve as a promising biomarker in diagnosis of PDAC. This evidence concerns the gene GDF15 and colorectal adenocarcinoma.