Related to Fig. 2 . (A) Western blot, with antibodies against IRF4 and vinculin, of total lysates from HEK293T cells with and without transfection with various IRF4 cDNAs or with EV. NT = not transfected. Representative data from two independent experiments are shown. (B) Dual luciferase ISRE-IFNB1 reporter activity of HEK293T cells transfected with EV or with various IRF4 cDNAs, combined or not with WT-IRF4 cDNAs. Data from three independent experiments performed in triplicate are shown. (C) Western blot, with antibodies against IRF4 and vinculin, of total lysates of EBV-B cells from three healthy controls (CTLs), patients (P1 and P2), and an individual heterozygous for the p.R98W IRF4 variant (11). Data representative of two independent experiments are shown. Source data are available for this figure: SourceData FS2.