Children with critical illness, such as sepsis, subsequently have a period of reversible immune dysfunction.1 This state of immunoparalysis is characterized by reduced monocyte function, including lower human leukocyte antigen DR isotype (HLA-DR) expression and reduced tumor necrosis factor alpha (TNF-α) production upon restimulation, increased risk of secondary infections and elevated mortality.1 A potent mediator of this process is lipopolysaccharide (LPS),2 also called endotoxin, a highly immunogenic component of the outer membrane of Gram-negative bacteria. This evidence concerns the gene TNF and immune system disorder.