STAT6 and infection: We analyzed by quantitative polymerase chain reaction (qPCR) the levels of iNOS (M1 macrophage marker) and arginase-1 (M2 macrophages marker) on CNS tissue from infected animals; on both groups (ST2−/−- and Stat6−/−-infected mice), the mRNA levels for iNOS (Fig. 6a), but not arginase-1 (Fig. 6b), were significantly upregulated at 9 days post-infection, compared to WT infected mice.