BCR and diffuse large B-cell lymphoma: DLBCL have been subdivided in three major molecular entities based on gene expression analysis [102]: (a) the germinal centre B-cell like derived (GCB) DLBCL, (b) the activated B-cell like (ABC) DLBCL which are related to BCR-activated B cells or B cells committed to plasma cell differentiation and (c) primary mediastinal B cell lymphoma (PMBCL), which arise from post-GC thymic B cells.