Coupled with the observation that CD205-deficient mice lacked overt signs of autoimmunity and adoptive transfer of Ly75−/− splenocytes into Nude hosts did not lead to overt signs of autoimmune disease (data not shown), it is suggested that T cell generation in the absence of CD205 expression does not lead to a breakdown in central tolerance. The gene discussed is LY75; the disease is autoimmune disease.