MUC1 and neoplasm: MUC1 expression was evaluated by immunohistochemistry stratifying samples according to staining intensity as tumor with high MUC1 expression (MUC1H; ≤ 50% positive tumor cells), tumor with low MUC1 expression (MUC1L; 50 − 20% positive tumor cells), and tumor that do not express MUC1 (MUC1neg).