In addition, patients with mono-allelic loss-of-function mutations of A20 develop mucosal and skin ulcers resembling Behçet’s disease as well as a growing number of other autoinflammatory and autoimmune disorders (Zhou et al., 2016; Ohnishi et al., 2017; Takagi et al., 2017; Aeschlimann et al., 2018). The gene discussed is TNFAIP3; the disease is autoimmune disease.