The study of the liver as a lymphoid organ is a growing field fueled by our better knowledge of the different component of the immune system and how they orchestrate an immune-related response. The liver have highly specialized mechanisms of immune tolerance, mainly because is continuously exposed to microbial and environmental antigens, and dietary components from the gut. Growing evidences show that the liver produces a pletora of neo-antigens being the primary metabolic organ of the body.

Common immune mechanisms play a key pathogenetic role in most of acute and chronic liver diseases and in the rejection of liver allografts.

Any perturbations of liver-related immune functions have important clinical implications, such as the development of autoimmune liver diseases, i.e. autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis, a great paradox for a tolerogenic organ.