A cluster of genes, BAT1-BAT5, has been localized in the vicinity of the genes for TNF alpha and TNF beta. These genes are all within the human major histocompatibility complex class III region. This gene has microsatellite repeats which are associated with the age-at-onset of insulin-dependent diabetes mellitus (IDDM) and possibly thought to be involved with the inflammatory process of pancreatic beta-cell destruction during the development of IDDM. This gene is also a candidate gene for the development of rheumatoid arthritis. Two transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Dec 2010].