IFNG and susceptibility to pneumonia measurement: To evaluate the effect of IFNγ against specific phases of immune response and to more realistically simulate the clinical sepsis patient setting, new studies could use either a two-step CLP model (CLP followed by Streptococcus pneumoniae induced pneumonia) or an endotoxin tolerance model (LPS pretreatment followed by establishment of CLP), but to address the high mortality rate of the two-step CLP model (Muenzer et al. 2006).