Comparing the AIP and PaCa 2D-DIGE protein expression data using the DeCyder image analysis, we found in sera of AIP patients three-fold higher levels of apolipoprotein A-I, 3.5-times higher levels of apolipoprotein A-II and two-fold higher levels of transthyretin (TTh). Here, APOA1 is linked to autoimmune pancreatitis.