SOCS1 mutations are enriched among GCB hot DLBCLs and enhance B-cell sensitivity to IFN-γ signaling. (A) PCA plot (left) and bar plot (right) showing the frequency of SOCS1 LoF alterations in each immune-related cluster. (B) Lollipop plots showing frequency and distribution of mutations in SOCS1 in GCB hot (top) and GCB cold (bottom) DLBCLs. (C) Immune cell deconvolution (CIBERSORTx) showing absolute inferred proportions of indicated immune cell subsets in SOCS1 LoF GCB DLBCLs compared with SOCS1 WT GCB DLBCLs. (D) GSEA plots showing upregulation of IFN-γ response genes and IFN-α response genes in SOCS1 LoF GCB DLBCLs compared with SOCS1 WT GCB DLBCLs. Fisher exact test with BH-adjusted P values for categorical variables. Kruskal-Wallis test followed by post hoc Dunn test with adjusted P values for continuous variables. (E) Fold change in MFI of H-2^b, I-A/I-E^b, and PD-L1 on CD19⁺ splenocytes. CD19⁺ splenocytes from Cd19^Cre/+ (n = 6) or Cd19^Cre/+Socs1^fl/fl mice (n = 6) were cultured with media or the indicated concentrations of IFN-γ for 48 hours, and expression levels of H-2^b, I-A/I-E^b, and PD-L1 were measured. Mice were pooled from 3 independent biological replicates. Two-way ANOVA with Bonferroni correction, adjusted P values displayed. ∗adjusted P < .05; ∗∗adjusted P < .01; ∗∗∗adjusted P < .001; ∗∗∗∗adjusted P < .0001. ANOVA, analysis of variance; BD, Benjamini-Hochberg; MFI, mean fluorescence intensity.