This disease is caused by excessive leukocyte activation, leading to the release of secondary inflammatory mediators [Interleukins (IL) ‐ IL‐1α, IL‐6, IL‐8, IL‐10, tumour necrosis factor (TNF‐α), platelet‐activating factor, nitric oxide (NO), arachidonic acid metabolites], resulting in massive inflammatory response, contributing to the induction of systemic inflammatory response syndrome (SIRS). This evidence concerns the gene TNF and systemic inflammatory response syndrome.