In contrast to what is commonly described in publications on PID (10, 12), our cohort included a high proportion of patients with combined deficiencies, such as Wiskott-Aldrich syndrome, activated PI3K-delta syndrome (APDS), ataxia telangiectasia, CTLA-4, or PMG3 deficiency. Here, CTLA4 is linked to Ataxia-telangiectasia.