40 Salzer Salzer U U Bacchelli Bacchelli C C Buckridge Buckridge S S Pan-Hammarstrom Pan-Hammarstrom Q Q Jennings Jennings S S Lougaris Lougaris V V Relevance of biallelic versus monoallelic TNFRSF13B mutations in distinguishing disease-causing from risk-increasing TNFRSF13B variants in antibody deficiency syndromes Relevance of biallelic versus monoallelic TNFRSF13B mutations in distinguishing disease-causing from risk-increasing TNFRSF13B variants in antibody deficiency syndromes Blood. Here, TNFRSF13B is linked to inborn error of immunity.