“CO44 | First interlaboratory validation workshop of immunofluorescence microscopy on the peripheral blood smear for recognizing patients with inherited platelet disorders: C. Zaninetti1, L. Bury2, V. Bozzi3, A. Zamora-Cánovas4, K. Althaus5, G. Uzun5, S. Brown6, A. Norman6, D. Faille7, A. Stepanian8, C. Freyer1, L. Kager9, T. Bakchoul5, A. Pecci3, P. Gresele2, T. Thiele1, J. Rivera4, A. Greinacher1 | 1Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Germany; 2Department of Medicine, Section of Internal and Cardiovascular Medicine, University of Perugia, Italy; 3Department of Internal Medicine, University of Pavia, Italy; General Medicine 1, IRCCS Policlinico San Matteo Foundation, Pavia, Italy; 4Servicio de Hematología, Hospital Universitario Morales Meseguer, Centro Regional de Hemodonacio´n, Universidad de Murcia, Spain; 5Institute for Clinical and Experimental Transfusion Medicine, University Hospital of Tuebingen, Germany; Center for Clinical Transfusion Medicine, Tuebingen, Germany; 6Centre for Children’s Health and Research CCHR, South Brisbane, Australia; 7Laboratoire d’Hématologie, Assistance Publique Hôpitaux de Paris, Hôpital Bichat-Claude-Bernard, Paris, France; 8AP-HP, Service d’Hématologie Biologique, Hôpital Lariboisière, Paris Cité University, Paris, France; 9St. Anna Kinderspital, Universitätsklinik für Kinder- und Jugendheilkunde der Medizinischen Universität Wien, Austria” (2025) Bleeding, Thrombosis and Vascular Biology, 4(s1). doi:10.4081/btvb.2025.250.