Four studies reviewed twelve genes encoding for cytokines and cytokine receptors (IL-1, IL-1B, IL-4, IL-6, IL-8, IL-12A, IL-12B, IL-17A, IL-17F, IL-23R, TNF-α, GM-CSF) in association with the development of PJI [14,20,22]. The gene discussed is TNF; the disease is juvenile polyposis syndrome.