In addition to IgM expression, which is associated with the activated B-cell-subtype of DLBCL,32 we observed an enrichment of ABC-associated gene mutations in the ECD-PCFCL group, conflicting with the uniform GCB signature as determined by the gene-expression-based Lymph2Cx algorithm. The gene discussed is CD40LG; the disease is diffuse large B-cell lymphoma.