Irf3−/−/Bcl2L12−/− (labeled KO) and B6 BMMs were unprimed or were primed with 10U/ml IFNγ, and infected with L. pneumophila. Cytoplasmic protein extracts were collected at the indicated timepoints after infection, and analyzed by Western blotting for STAT1pY701, STAT1pS727, total STAT1, and β-actin. Results are representative of three independent experiments. The slight increase in STAT1pY701 seen in IFNγ-primed Irf3−/−/Bcl2L12−/− BMMs relative to B6 BMMs at 0hpi was not seen in the other two experiments, and is considered to be insignificant.