BCL6 and diffuse large B-cell lymphoma: Owing to an understanding of the biology of DLBCL, the cell of origin (COO), MYC arrangement with either additional BCL-2 or BCL-6 gene rearrangements, and dual expression have been identified as adverse prognostic indicators for de novo DLBCL as well as for secondary CNS involvement in DLBCL [15, 21].