1. Clinic for Pediatric and Adolescent MedicineUniversity HospitalFrankfurt Germany
2. GMP Development UnitInstitute of Cellular Therapeutics, IFB‐TX, Hannover Medical SchoolHannover Germany
3. Division for Cell ProcessingInstitute for Transfusion Medicine and Immunohematology, Goethe‐University Frankfurt/Main
4. German Red Cross Blood Donor Service, Baden‐Württemberg‐HessenFrankfurt/Main, Germany.