Obviously, the role of NK cells in FAP disease is very controversial and little is known about the expression of NK cells effector molecules during FAP progression, such as adhesion molecules, Fas ligand (FasL), tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), NKp44, granzymes, as well as cytokine production (58). This evidence concerns the gene TNF and Familial adenomatous polyposis.