STAT1 and lymphopenia: We saw a peripheral blood lymphopenia correlating with increasing disease severity, similar to observations made in Stat-1-/- [5] and Rag2-/- mice [10], and increases in plasma levels of pro-inflammatory cytokines (IL-6 and IL-18) and chemoattractants (CCL2, CXCL1, and CXCL10) reported in the C57BL/6J (BL6) IFN-1-blockade disease model [10].