Upon exposure to pro-inflammatory signals such as interleukin-1 (IL-1), interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α) cytokines, M1 macrophages activate further pro-inflammatory responses such as additional cytokines, neutrophils and T cells that produce a heightened inflammatory response at the site of infection or injury. This evidence concerns the gene IL6 and infection.