Mutations of TNFRSF13B/TACI are also found in healthy individuals, albeit at lower frequency than in CVID cohorts: the frequency of normal individuals carrying the C104R variant (0.8%) is higher than the prevalence of disease (0.002%).10 This suggests either these mutations of TACI are clinically inconsequential in many cases, or there are other additional unknown genetic defects in symptomatic patients that contribute to the disease phenotype.11, 12. This evidence concerns the gene TNFRSF13B and common variable immunodeficiency.