PTPRC and neoplasm: While aggregates of CD138+B220− plasma cells were found in the spleen, bonemarrow, and/or tumor in 12Mef−/−Rad50s/s mice (80%), no plasma cell aggregates wereobserved in wild type orMef−/− mice; this toorepresents a significant abnormality (p < 0.0001:Mef−/−Rad50s/s vs wild type,p < 0.0001:Mef−/−Rad50s/s vsMef−/−).