 "Pseudomonas" can develop special characteristics that allow the formation of large colonies, known as "mucoid" "Pseudomonas", which are rarely seen in people who do not have CF.Scientific evidences suggest the interleukin 17 pathway plays a key role in resistance and modulation of the inflammatory response during "P. aeruginosa" infection in CF.In particular, interleukin 17-mediated immunity plays a double-edged activity during chronic airways infection; on one side, it contributes to the control of "P. aeruginosa" burden, while on the other, it propagates exacerbated pulmonary neutrophilia and tissue remodeling.