IFNA1 and infection: We confirmed by ELISA the lower levels of IFN-α in ChemR23−/− compared to WT mice in lung homogenates (49±16 versus 158±51 pg/ml respectively; p<0.05), and BAL fluids (91±26 versus 239±46 pg/ml respectively; p<0.01) at day 8 post-infection.