Intraductal pancreatic mucinous neoplasm (IPMN) often shows positivity for MUC5 and MUC6 in the gastric and pancreaticobiliary types and positivity for MUC2 and MUC5 in the intestinal type, but these markers were all negative in this tumor. The gene discussed is MUC2; the disease is pancreatic intraductal papillary-mucinous neoplasm.