“…The ANKENT and SIA models have been described using different B27 transgenes (B*2702 and B*2705, respectively (Krimpenfort et al 1987;Nickerson et al 1990), as well as independently produced ko founders (Zijlstra et al 1989;Koller and Smithies 1989, respectively). Moreover, ANKENT and SIA have distinct pathological characteristics: nail changes, synovial inflammation, and phalangeal joint involvement are present in SIA (Khare et al 1995) but absent in ANKENT (Weinreich et al 1995a). SIA occurred only when mice were moved from a specific-pathogen-free to a conventional unit, suggesting that an environmental trigger, in addition to abnormal transport or expression of B27 heavy chain, is involved (Khare et al 1995).…”