FASLG and Familial adenomatous polyposis: 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).