GCB-DLBCL presents intra-clonal heterogeneity, somatic hypermutation, and CD10 and B-Cell Lymphoma 6 (BCL-6) expression, while ABC-DLBCL has constitutive activity of NF-kB and expression of B-Cell Lymphoma 2 (BCL-2) and Interferon Regulatory Factor 4 (IRF4) [4]. The gene discussed is IRF4; the disease is aneurysmal bone cyst.