TNF and infection: The discrepancy between the results obtained with AMs from LysM-cre × Hif1αfl/fl mice (reduced TNF production upon LPS stimulation in vitro, Figure 1) and LysM-cre × Hif1αfl/fl mice after infection with viable K. pneumoniae via the airways (higher TNF levels in whole lung homogenates at 12 hours after infection, Figure 3(a)) prompted us to study macrophage-specific TNF production in whole lung cell suspensions exposed to heat-killed K. pneumoniae.