His areas of interest is the hematological neoplasias, with special emphasis on the study of pathophysiology and the development of new treatment strategies for acute leukemias. Among his most cited works are: "Retinoic acid (RA) and As2O3 treatment in transgenic models of acute promyelocytic leukemia (APL) unravel the distinct nature of the leukemogenic process induced by the PML-RAR alpha and PLZF-RAR alpha oncoproteins" Proceedings of the National Academy of Sciences of the United States of America (2000); "Role of promyelocytic leukemia (PML) protein in tumor suppression" - Journal of Experimental Medicine (2001); "Identification of a myeloid committed progenitor as the cancer-initiating cell in acute promyelocytic leukemia" - Blood (2009) and "Improving acute promyelocytic leukemia (APL) outcome in developing countries through networking, results of the International Consortium on APL" - Blood 2013). He is a Member of the Steering Committee and Coordinator in Brazil of the International Consortium of Acute Leukemias (ICAL) of the American Society of Hematology. The clinical studies developed by ICAL in Latin America aim to improve the outcomes of treatments for acute leukemias in the region and promote the scientific advancement of hematology. Prof. Rego is the Vice-Chair of International Members Committee of the American Society of Hematology and Scientific Vice-Director of the Brazilian Association of Hematology and Hemotherapy (2018/2019). He is Editor of the Brazilian Journal of Medical and Biological Research; Deputy Editor of Hematology, Transfusion and Cell Therapy Journal (HTCT) and Associate Editor of the Annals of Hematology. Member of the Health Area Coordination of the Foundation for Research Support of the State of São Paulo (FAPESP) (2007-2019)