However, in other scenario were endogenous MPO is not an autoantigen (like collagen-induced arthritis, pristine-induced lupus nephritis or healthy donors) MPO attenuates or even suppresses T cells responses, including decreased proliferation of human T cells in vitro [44], lower DC activation and migration, showing an increased proliferation, activation and proinflammatory cytokine production in MPO−/− mice [6]. Here, MPO is linked to lupus nephritis.