Neutrophils are the first line of defense of the immune system against infection. Among their weaponry, they have the ability to mix and extrude their DNA and bactericidal molecules creating NET-like structures in a unique type of cell death called NETosis. This process is important in order to control extracellular infections limiting collateral damage. Its aberrant function has been implicated in several human diseases including sepsis and autoimmune disease. The purpose of the present paper is to give a general introduction to this concept.