Low penetrance variants in TNFAIP3, encoding A20, have been associated with many different complex immune mediated diseases (86), but more recently, heterozygous loss-of-function variants have established an autoinflammatory disease entity termed A20 haploinsufficiency (MIM: 616744), with similarities to Bechet’s disease and autoimmune lymphoproliferative syndrome (ALPS) (23, 87, 88). Here, TNFAIP3 is linked to autoimmune lymphoproliferative syndrome.