MUC6 and ovarian mucinous neoplasm: A previous study indicated that ovarian mucinous tumors show similar mucin immune-profile being strongly and uniformly positive for MUC5AC irrespective of whether they are benign, borderline or malignant, but only focally positive for MUC1, MUC2, and MUC6, which is different from pancreatic, biliary, esophageal, gastric, and colorectal/appendiceal carcinomas [27,28].