DBA/1J-lpr/lpr and DBA/1J-lpr/+ mice were scored for arthritic lesions as described in Materials and methods. A summary of disease course in DBA/1J-lpr/lpr and their control littermates DBA/1J-lpr/+ is shown. a18 of the lpr/lpr mice and 16 of the lpr/+ mice are from Ma and co-workers . bNumber of diseased mice divided by all mice. cScore of diseased mice divided by all mice ± SEM. dTotal of days of onset divided by the number of diseased mice ± SD. * eP < 0.05, χ2 test. * fP < 0.05, Mann–Whitney U test.