KMT2D and diffuse large B-cell lymphoma: This subgroup, representing ~60% of HGBCL, NOS, lack gene‐expression signature of BL and double hit/dark zone lymphoma, but express DLBCL like signatures and are characterized by either GCB‐ or ABC‐like mRNA signatures and exhibit higher genomic complexity, similar to de novo DLBCL, and show alteration in genes regulating B‐cell activation (CD79B, MYD88, PRDM1, TBLIXR1, CARD11), epigenome (KMT2D, TET2) and cell cycle transition (TP53, ASPM).