IL6 and Sepsis: Studies evaluating the immune functions of peripheral blood cells have evidenced a broad impairment of the response: monocytes from septic patients have shown decreased HLA-DR expression and production of TNF-α and IL-6 after stimulation in vitro; neutrophils have been reported to present decreased chemotaxis, phagocytosis, and reactive oxygen species (ROS) generation, and importantly, decreased lymphocyte counts with reduced functionality are observed during sepsis (24, , , –28).