Specifically, IKZF1 variants are associated with common variable immunodeficiency (CVID), cytopenias, malignancy, combined immunodeficiency (CID), and immune dysregulation [13, 14], DN and LOF variants in IKZF3 are associated with B cell lymphopenia, malignancy, and susceptibility to Pneumocystis jirovecii pneumonia [15, 16], and LOF variants in IKZF5 are associated with thrombocytopenia [17]. Here, IKZF1 is linked to common variable immunodeficiency.