Collagen-induced arthritis (CIA) is a polyarthritis induced by sensitization of susceptible strains of animals with collagen II (the major collagen of hyaline cartilage). Because the original description of the model in rats by Trentham et al. ( 1 ), it has become clear that species including rats, mice, and primates can develop CIA. In this respect, the disease is quite different to adjuvant-induced arthritis, which appears to be a disease restricted to rats. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.