Inagaki et al. have demonstrated that MUC1 can be used effectively to diagnose intraductal papillary mucinous neoplasms (IPMN) with IPMC; all PDAC specimens were positive on immunohistochemical analysis for KL-6 mucin (unpublished data [13]). The gene discussed is MUC5AC; the disease is pancreatic intraductal papillary-mucinous neoplasm.