Expression of IFNAR1 by the patients’ fibroblasts. (A) IFNAR1 mRNA levels in SV40-fibroblasts from two healthy controls (C1, C2), and patients with IFNAR1 variants: P335del/P335del, P335del/+, W73C/W73C, V225fs/+, and V225fs/V225fs. GUS was used as an expression control. Graphs depict the mean ± SEM of two independent experiments, each with three technical duplicates. (B and C) Flow cytometry histograms of cell-surface expression for IFNAR1 (B) and IFNAR2 (C), with extracellular staining of SV40-fibroblasts from healthy controls and patients. Antibodies recognize the extracellular parts of IFNAR1 or IFNAR2. Each histogram plot is representative of two independent experiments.