In line with this hypothesis, increased lethality and severity of the infection by A. baumannii was observed when neutrophils were depleted, together with a delayed production of cytokines involved in neutrophil function, such as TNF-α, interleukin 1, keratinocyte chemoattractant protein (KC/CXCL1) and macrophage inflammatory protein (MIP-1) [17]. This evidence concerns the gene CALCA and infection.