Relapsed DLBCL-NOS patients carried mutations in several of the same genes as primary OA-DLBCL-NOS, including pathogenic variants in PIM1 (n = 3), CD79B (n = 3), and MYD88 (n = 2), as well as other genes linked to the MCD subtype: BTG1 (n = 2), BTG2 (n = 2), KLHL14 (n = 2), ETV6 (n = 2), IRF4 (n = 2), and CDKN2A loss (n = 2) [7,8]. This evidence concerns the gene IRF4 and diffuse large B-cell lymphoma.