In summary, the results obtained in this retrospective, monocentric post-hoc analysis are the first data in ravulizumab-treated adult PNH patients investigating IgG concentrations over a longitudinal course, showing that IgG and IgG subclass levels which are regulated by the FcRn remain unaffected. The gene discussed is FCGRT; the disease is paroxysmal nocturnal hemoglobinuria.