The figure shows a schematic of the TNFAIP3 gene locus, which encodes A20. Exons encoding the amino-terminal OTU domain are shown in orange and exons encoding the carboxy-terminal zinc fingers (ZFs) of A20 are shown in green. The C103, ZF4 and ZF7 motifs are highlighted. Non-coding exons, including AT-rich sequences at the end of exon 9, are shown in brown. Human germline single-nucleotide polymorphisms (SNPs) in the TNFAIP3 locus that are associated with autoimmune and autoinflammatory diseases are indicated (labelled with their reference SNP (rs) numbers)26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46, as are somatic mutations that have been identified in the coding exons of TNFAIP3 in human B cell lymphomas50,51,52,53,54.