FOXO1 expression in lymphoid FL, HL, and NHL. (A) FOXO1 expression in tonsillar lymphoid follicle. Low magnification image represents immunohistochemical staining of FOXO1 distribution in the whole follicle (original magnification ×50). High-magnification images show FOXO1 expression in cells of dark zone containing centroblasts (DZ) and light and marginal zone containing centrocytes and resting B cells, respectively (LZ and MZ; original magnification ×200). (B) FOXO1 expression in BCLs. Neoplastic cells of cHL and LPHL are FOXO1-negative (original magnification ×200). Objective: Plan-Neofluar 10×/0.3 NA for the low magnification of normal lymphoid follicle and Plan-Neofluar 40×/0.75 NA objective for the high magnification normal lymphoid follicle and lymphoma images.