NAC or vitamin-E treatment increases the histopathological grade of advanced tumors. (A) Schematic of the study design. NAC or VitE were supplemented in the drinking water or chow diet of APCMin/+ mice from 12 until 19 weeks of age. (B) Tumor numbers in one sagittal section of the small intestine of 19-week-old APCMin/+ mice (n = 8 Ctrl, 8 NAC, 6 VitE). (C,D) The geometric mean area (C) and size distribution (D) of individual tumors in the small intestines of 19-week-old APCMin/+ mice (n = 117–158 tumors, error bars indicate 95% confidence intervals). (E,F) Distribution graphs showing the percentage of adenomas with HGD or LGD (E), or sessile serrated lesions (SSLs) with or without dysplasia (F), in the small intestines of 19-week-old APCMin/+ mice (n = 47–67 adenomas, 10-17 SSLs). HGD, high-grade dysplasia; LGD, low-grade dysplasia. **** p < 0.0001.