Pathological changes.(A) Colons were excised 10 weeks after AOM injection (left) and were longitudinally opened (right). (B) Colons were excised 20 weeks after AOM injection and were stained with H&E. (C) Squamous metaplasia, adenoma, high grade intraepithelial neoplasia and adenocarcinoma were found in WT group and NPC1L1−/− group. (Scale bars represent 400 μm.) (D) NPC1L1−/− mice had a lower ratio of malignant tumor/tumor than WT mice. *p < 0.05.