Characterization of human CD4 ⁺ FCRL3 ⁺ T cells. (A) Volcano plot showing the differentially expressed genes for FCRL3⁺ versus FCRL3⁻ memory CD4⁺ T cells from N = 5 independent donors, analyzed by RNA-seq (FDR ≤ 0.05 and log₂FC ≥|0.5|). (B) Venn diagrams showing the intersection of the genes differentially expressed in memory CD4⁺ and CD8⁺ T cells. (C) Heatmaps showing the log₂FC of selected genes from (A and E). (D) Granzyme B expression (by intracellular staining) in sorted CD4⁺ FCRL3⁺ and FCRL3⁻ memory T cells. N = 6, mean ± SD; paired t test, two-tailed. *P = 0.0419. (E) Volcano plot showing the differentially expressed genes for FCRL3⁺ versus FCRL3⁻ Treg cells from N = 5 independent donors, analyzed by RNA-seq (FDR ≤ 0.05 and log₂FC ≥|0.5|). (F) Venn diagrams showing the intersection of the genes differentially expressed in memory conventional CD4⁺ T cells and Tregs. (G) Screenshot of FOXP3 expression in FCRL3⁺ and FCRL3⁻ Tregs, conventional memory CD4⁺ and CD8⁺ T cells, by RNA-seq. (H) IFN-γ production by FCRL3⁺ and FCRL3⁻ CD8⁺ or CD4⁺ memory T cells. Intracellular cytokine staining was performed upon stimulation with PMA and ionomycin for 5 h. The dot plots are from one representative donor; the histograms show the results from different donors (N = 5–11), with each dot representing one donor; mean ± SD; paired t test, two-tailed. n.s.: not significant, **P = 0.004. FC, fold change. Data underlying this figure can be found in Data S4.