We also analyzed the expression of TGF-α in human pancreatic lysates and found that in human chronic pancreatitis (CP), which is a potential precursor of human PDAC, the tissue levels of TGF-α were markedly lower than in human PDAC tissues (ΔΔ Ct/2–ΔΔCt of CP: 0.14 ± 0.06 versus PDAC: 0.62 ± 0.18, p=0.017, Mann Whitney U test, Supplemental Figure 4F). This evidence concerns the gene TGFA and chronic pancreatitis.