ZAP70 and arthritic joint disease: To ensure these observations were not attributable to the mutation in Zap70 that predisposes SKG mice to autoimmune responses, we confirmed that inflammation induced by intraperitoneal (IP) injection of curdlan in WT C57BL/6 mice produces the same hematopoietic phenotype after 1 wk (i.e., increased GMP and decreased CFU-E percentages and absolute numbers; Fig. S1, I and J) but does not induce clinical arthritis (data not shown).