CD20, CD3, and SH2D1A expression on serial sections of DLBCL. Immunohistochemical staining of CD20 (A, E), CD3 (B, F), and SH2D1A (C, G) on paraffin-embedded sections. DAB staining shows specific reactions in brown. (D, H) Double-staining of CD3 (DAB substrate in brown) and SH2D1A (Fast Red substrate in red). GC-DLBCL (A-D) and ABC-DLBCL (E-H). Original magnifications: 400 × (A-G), 1000 × (H).