ELISA results showed that 30 (81.1%), 8 (21.6%), 5 (13.5%), and 4 (10.8%) of 37 patients with PSC possessed IgG1, IgG2, IgG3, and IgG4 antibodies, respectively (Fig. 3a). This evidence concerns the gene IGHG3 and pancreatic serous cystadenoma.