STAT1 and infection: Interestingly, and similar to that observed in mice with B cell-specific STAT1 deficiency (Fig. 2 and 5), B cell-specific IFNAR1 deficiency resulted in a 4.4-fold increase in the frequency of MHV68 DNA-positive peritoneal cells at 16 days post-infection (Fig. 8A, compare to the 3.6-fold increase observed in the mouse model of B cell-specific STAT1 deficiency, Fig. 2D).