Variants in additional genes (not listed as “CVID genes” in OMIM), including BLK, CD27, CD70, CTLA4, IL21R, PIK3CD, PIK3R1, PLCG2, PRKCD, RAC2, TNFSF12 and VAV1 have also been associated with CVID (4, 8–10). Here, PIK3R1 is linked to common variable immunodeficiency.