Genetic analyses of subjects with a CVID phenotype have identified recessively inherited traits with biallelic mutations in ICOS, CD19, CD20, CD21, CD81, PRKCD, and LRBA, and autosomal dominant traits with monoallelic mutations in PIK3CD, NFKB2, PIK3R1 (1), and, most recently, NFKB1 (3) and, as we have shown, IKZF1 (4). This evidence concerns the gene LRBA and common variable immunodeficiency.