In fact, most of the previously reported biomarkers for PDA (e.g., CA19-9, CEA, α-fetoprotein, MMP-7, cathepsin D, integrin B1, HSP27, elastase-1, MCSF and CA195) are expressed by epithelial tumor cells, while Gal-1 is specifically expressed and released by pancreatic-activated fibroblasts. The gene discussed is CTSD; the disease is Patent ductus arteriosus.