RASA3 and Decreased total leukocyte count: Western blotting confirmed loss of RASA3 protein in Mx1-Cre; Rasa3 mutant red cell membranes within 2 weeks of the final Poly(I:C) injection (Fig 4A) at which time the mice are profoundly anemic and thrombocytopenic with significant leukopenia (Fig 4B and Table 1).