The digenic etiologies associated with CVID phenotypes with antibody production deficiencies and autoimmunity relating to clinical epistasis, and including variants in genes such as NFKB1 and NOD2 (Nucleotide-binding oligomerization domain containing 2) [45], LRBA and NEIL3 (Nei-Like DNA Glycosylase 3) [46], and CTLA4 and JAK3 (Janus Kinase 3) [47], have been summarized in Table 2. Here, CTLA4 is linked to common variable immunodeficiency.