TNFAIP3 and Arthritis: Heterozygous LoF mutations in TNFAIP3 gene are associated with Haploinsufficiency of A20 (HA20), a childhood-onset systemic autoinflammatory disease manifesting with recurrent fever, arthritis, oral and/or genital ulcers, skin allergies, gastrointestinal inflammation, eye inflammation and autoimmunity (71, 72).