Immunohistochemical patterns of CD20, FOXP3 TIA-1, and PD-1 expression. (A) FOXP3 nuclear positivity in numerous reactive lymphocytes (IHC score 3), but not in Reed-Sternberg cells (inset) in a cHL case with favorable outcome. In contrast, only rare scattered FOXP3-positive lymphocytes (IHC score 1) are observed in a cHL case with unfavorable outcome (B). TIA-1 positivity in cHL cases with poor outcome was frequently observed as high (IHC score 3) (C), whereas cHL cases with favorable outcome often display a low level (IHC score 1) of TIA-1 expression (D). (E) CD20 reactivity on a TMA core from a case of cHL with unfavorable outcome, which contained only scarce positive reactive lymphocytes (IHC score 1), compared with the strong CD20 positivity (IHC score 3) of a case of cHL with favorable outcome (inset). PD-1 immunostaining was detected in a minority of reactive lymphocytes in most cHL cases (F), whereas Reed-Sternberg cells are negative (F, ). As expected from cDNA microarray data, the PD-1 antibody strongly stained the vast majority of reactive T lymphocytes in H/TCRBCL cases (G), whereas neoplastic B cells were negative, as evidenced by high-power view (H, ). Panels A-D and G were obtained using a 20×/0.6 objective lens (×200 magnification). Panel E was obtained using a 10×/0.32 objective lens (×100 magnification). Panels F and H correspond to a 40×/0.75 lens (×400 magnification).