MUC5AC and pancreatic ductal adenocarcinoma: And the results in the present study indicated that the mucin phenotypes of the atypical MGH (PanIN-1B by PanIN system) had a diffusely positive reaction for both anti-MUC1 staining and anti-45M1 staining, and had a spasely positive reaction for anti-Ki-67 staining, and these findings resembled those of the pancreatic ductal carcinoma (PDC), except for the expression of p53 (MGH: negative, PDC: positive).