TNFAIP3 (TNF Alpha Induced Protein 3): TNFAIP3, also known as A20, is a crucial negative regulator of NF-κB signalling, aiding the control of inflammation and immune responses. It functions by ubiquitinating signalling molecules to halt NF-κB activation, thus preventing prolonged inflammation that could result in autoimmune disease. Mutations or dysregulation of TNFAIP3 are associated with various autoimmune and inflammatory conditions, making it a significant focus of therapeutic research.