TNFAIP3, also known as A20, is located in chromosome band 6q23, a region that is often deleted in B cell lymphomas. Recently, it was identified as a tumor suppressor gene in Hodgkin lymphoma and several subtypes of non-Hodgkin lymphomas. TNFAIP3 was initially identified as a zinc-finger protein that is rapidly and transiently induced by TNF-α, inhibiting NF-κB-dependent gene expression, and protecting cells from TNF-α-cytotoxicity. Overexpression of TNFAIP3 also inhibits the TLR2- and TLR4-mediated interleukin-8 synthesis in airway epithelial cells, suggesting that TNFAIP3 also acts as a negative regulator of TLR-mediated inflammatory responses, thereby protecting the host against harmful over-responses to pathogens. At least two isoforms of TNFAIP3 are known to exist.