To investigate the potential suitability of GM-CSF as a therapeutic agent for the enhancement of innate immunity, we performed whole blood experiments using therapeutic concentrations of GM-CSF and similar endotoxin concentrations to those occurring in human septic shock [31, 32], while keeping exposure to stimuli as short as possible in order to avoid anergy of monocytes and neutrophils (no recruitment of new functional monocytes and neutrophils in vitro). Here, CSF2 is linked to septic shock.