RAG1 and RAG2 mutations in humans are associated with a broad spectrum of clinical and immunological phenotypes, including T− B− severe combined immune deficiency (SCID) (13), Omenn syndrome (OS) (14), atypical SCID (AS) (15–17), and combined immune deficiency with granuloma and/or autoimmunity (CID-G/A) (18–21). Here, RAG2 is linked to Immunodeficiency.