MUC5AC and carcinoma: Among mucins with increased expression in SBC, MUC1 (Figures 2A and 2B) showed apical and cytoplasmic expression in carcinoma cells, but not in normal epithelium; MUC5AC (Figures 2C and 2D) showed cytoplasmic expression in carcinoma cells, but not in normal epithelium; and MUC16 (Figures 2E and 2F) showed apical expression in carcinoma cells, but not in normal epithelium.