On the contrary, based on immunohistochemical staining, Byers et al. reported that HHLA2 expression was decreased or absent in pancreatic adenocarcinoma tissue, although highly expressed in normal ductal epithelium or intraductal papillary mucinous neoplasms [18]. This evidence concerns the gene HHLA2 and pancreatic intraductal papillary-mucinous neoplasm.