At least 13 loci have now been confidently confirmed as being associated with RA susceptibility, and further insights into the genetic contribution to disease are likely to be revealed in the next 12 months. From the genes identified to date, it is clear that immune dysregulation plays a key role in susceptibility to RA, and that variation in the same loci may predispose to other autoimmune diseases. Although there are some inflammatory arthritis-specific genes, the majority do not show exclusive association with RA; therefore, it remains unclear as to what determines the pattern, extent, and progression of disease.