PD-L1 is not a negative prognostic biomarker in de novo DLBCL and may be associated with better prognosis in some patients, similar to macrophages and STAT3. (A) High PD-L1 protein expression (IHC 2+, 3+) by SP263 is associated with prolonged PFS in de novo DLBCL (MAIN). (B) Forest plot of HRs and 95% CIs for the association of PD-L1 expression and PFS with regard to different PD-L1 IHC reagents (SP142, SP263), the PD-L1 transcript (CD274 mRNA), and distinct DLBCL COO subgroups in MAIN and GOYA. High expression of a macrophage gene signature correlates with prolonged PFS (C) and adds prognostic information to DLBCL COO (D-E). (F) High expression of STAT3 mRNA correlates with prolonged PFS in de novo DLBCL (GOYA). Hazard ratios adjusted for IPI and treatment (MAIN) or IPI, treatment, region, and number of chemotherapy cycles (GOYA). Uncl, unclassified.