FcγRIIA modulates the platelet transcriptome during SLE. (A) Volcano plots of RNA sequencing–based analyses of the platelet transcriptome from B/WF1.FcγRIIA^Null and B/WF1.FcγRIIA^TGN mice aged 9 and 28 weeks (SLE develops by 28 weeks). Red dots represent significantly upregulated (false discovery rate [FDR] <0.05) genes, and blue dots represent significantly downregulated (FDR <0.05) genes. (B) Fold changes for genes contributing to an IFN-α/IFN-β pathway enrichment (FDR = 0.01) in B/WF1.FcγRIIA^TGN mice aged 28 vs 9 weeks compared with respective fold changes in B/WF1.FcγRIIA^Null mice aged 28 vs 9 weeks. Gene label H2- refers to the mean fold change for 9 different MHC loci that increased: H2-Bl, D1, K1, Q1, Q10, Q2, Q4, Q6, and Q7. (C) Gene set enrichment analysis directly comparing platelets from 28-week old B/WF1.FcγRIIA^Null and B/WF1.FcγRIIA^TGN mice identified significant (FDR <0.05) positive enrichment (TGN > Null) for 17 pathways. Shown is the enrichment score (ES) plot for the IFN-α/IFN-β Reactome signaling pathway, which had the largest ES and lowest FDR q value. padj, P value adjusted.