TPO and thyroid gland disorder: Furthermore, one of the several mechanistic hypotheses underlying the coincidence of multiple autoimmune conditions is that various tissues share the same epitopes, to which autoantibodies can cross-react.42 In this context, Benvenga et al43 recently showed an interesting amino acid sequence homology between thyroid autoantigens and central nervous system proteins, including TPO, autoantibodies to which are a characteristic biomarker for Hashimoto's hypothyroidism.