The mutational findings in the HGBCL-DH-BCL2 lymphoma subtype are relatively homogeneous and similar to those of FL, harboring frequent molecular abnormalities in BCL2, KMT2D, CREBBP, TNFRS14, and EZH2. Several recent studies described DLBCL cases with a gene expression signature (GEP) similar to that of HGBCL (DH-like GEP signature) [84–86] and have frequent mutations in MYC, BCL2, DDX3X, TP53, and KMT2D [85] (Table 1 and Fig. 1). The gene discussed is KMT2D; the disease is lymphoma.