Primary DLBCL in immune-privileged sites exhibits high-frequency mutations in MYD88 and CD79B, and nodal DLBCL exhibits high-frequency mutations in KMT2D, PIM1, BCL2, CREBBP, and EZH2. However, these mutations rarely occur in GI-DLBCL. This evidence concerns the gene KMT2D and diffuse large B-cell lymphoma.