The mechanisms responsible for activation of the BCR pathway in GCB DLBCL until very recently remained unknown, despite the long-standing evidence that the BCR-proximal kinase SYK is activated in a substantial proportion of GCB DLBCL cell lines and primary GCB DLBCL tumor samples [93,94,95,96]. This evidence concerns the gene SYK and diffuse large B-cell lymphoma.