NICD1 immunohistochemical staining in normal and tumor tissue. NICD1 immunohistochemical staining in normal and tumor tissue. A and B, normal tonsil tissue with nuclear staining in suprabasal epithelial layer. C and D, tumor tissue with nuclear staining in peripheral pattern, sparing outermost layer. E and F, tumor tissue with nuclear staining in nonperipheral pattern. G and H, tumor tissue with negative staining in tumor cells. Magnification: B, ×10; A, C to H, ×20. Eleni M. Rettig et al. Cancer Prev Res 2015;8:287-295 ©2015 by American Association for Cancer Research