DHITsig expression extends beyond HGBCL-DH-BCL2 to identify DZ lymphomas. (A) Characterization of DHITsig^pos tumors with DLBCL morphology. Left bar: GEP-based classification of all tumors with DLBCL morphology in the study population using the DLBCL90 assay (Nanostring), based on the algorithm in supplemental Figure 1. Central bar: COO classification of DHITsig^pos tumors. Right bar: HGBCL-DH-BCL2 status of DHITsig^pos tumors as determined by FISH. Tumors negative for HGBCL-DH-BCL2 are classified as DLBCL, NOS according to WHO HAEM5. (B) Heat map showing normalized expression of DHITsig genes in 55 BL tumors from an independent cohort and 431 germinal-center B-cell-like tumors with DLBCL morphology (GCB-DLBCL) from the study population. (C) Proportion of DHITsig^pos tumors in BL (left bar) vs GCB-DLBCL (central bar). All profiled BL tumors were DHITsig^pos. Right bar: proportion of DHITsig^pos GCB-DLBCL tumors that are HGBCL-DH-BCL2 vs DLBCL, NOS. (D) Proportion of tumors positive for the germinal center marker CD10 by IHC in BL and GCB-DLBCL in the presence (GCB-DLBCL DHITsig^pos) or absence of DHITsig (GCB-DLBCL DHITsig^neg/ind), compared with χ² test. IND, indeterminate; morph, morphology; NA, not available; NEG, negative; POS, positive; WHO HAEM5, 5th edition of the World Health Organization Classification of Haematolymphoid Tumors.