In a large cohort of additional 52 RT-DLBCLs managed at MD Anderson Cancer Center, co-expression of CD10 and BCL6 was documented by immunohistochemistry in only one sample, whereas PAX5 and IRF4 were expressed in virtually all RT-DLBCL samples (Tables S1 and S2). Here, IRF4 is linked to diffuse large B-cell lymphoma.