Our results suggest that serum exosome-based THBS2 could be a better biomarker for PDAC, with a higher AUC value, in discriminating not only between healthy control and early-stage PDAC but also between non-cancerous conditions (e.g., IPMN and pancreatitis) and all stages of PDAC, regardless of CA19-9 levels. The gene discussed is THBS2; the disease is pancreatitis.