MLH1 expression inDLBCLs. Immunohistochemical analysis of MLH1 protein expression in paraffin sections from representative DLBCL primary biopsies. (A) A representative DLBCL sample harboring the MLH1 rs1799977 AA genotype and characterized by a strong nuclear positivity for MLH1. (B) A representative DLBCL sample harboring the MLH1 rs1799977 GG genotype and characterized by a weak nuclear positivity for MLH1. Tissue microarray, immunoperoxidase, hematoxylin counterstain. Images were taken using a Nikon Eclipse 80i microscope (Nikon) with a pan fluor 20×/0.13 objective and Nikon digital sight DS-Fi1 camera equipped with control unit-DS-L2 (Nikon). Images were assembled using Adobe Photoshop 6 (Adobe Systems).