He also spent a short-term fellowship of Pediatric Clinical Immunology and Bone Marrow Transplantation in the Newcastle General Hospital. Professor Rezaei is now the Full Professor of Immunology and Vice Dean of Research, School of Medicine, Tehran University of Medical Sciences, and the co-founder and Head of the Research Center for Immunodeficiencies. He is also the Founder of Universal Scientific Education and Research Network (USERN). Prof. Rezaei has already been the Director of more than 100 research projects and has designed and participated in several international collaborative projects. Prof. Rezaei is an editorial assistant or board member for more than 30 international journals. He has edited more than 100 international books, has presented more than 500 lectures/posters in congresses/meetings, and has published more than 1,200 scientific papers in the international journals.