BCL6 and diffuse large B-cell lymphoma: However, CD10- and MUM1-positive cases and cases that were negative for CD10, BCL6, and MUM, showed different clinical characteristics and prognosis to others that were assigned to the same cell-of-origin group, indicating that the story is not complete, and calls for a consensus meeting on the use of immunohistochemistry to determine DLBCL subgroups.