It would be of great clinical importance to study the vasodilatory potency of GTN and development of nitrate tolerance under chronic GTN therapy in human individuals with Morbus Meulengracht (Gilbert's syndrome) to translate our preclinical data from bench to bedside and to further explore the therapeutical potential of HO-1 induction to overcome the side effects of GTN therapy. This evidence concerns the gene HMOX1 and Gilbert syndrome.