High and low blood serum PRX3 protein levels detected via ELISA showed significant positive correlations with PDAC diagnosis (p = 0.012), extrapancreatic nerve plexus invasion (pPL) (positive vs. negative, p = 0.045), gender (male vs. female, p = 0.023), diabetes (positive vs. negative, p = 0.001), lipase (>35 U/L vs. 0–35 U/L, p = 0.025), gamma glutamyl transferase (γGT) (>60 U/L vs. 5–60 U/L, p = 0.009), alkaline phosphatase (ALP) (>360 vs. 115–359 IU/L, p = 0.004), and alanine transaminase (ALT) (>28 IU/L vs. 6–27 IU/L, p = 0.022). This evidence concerns the gene GPT and diabetes mellitus.