Osato has been studying the molecular mechanism of leukemogenesis by RUNX and related genes, using cell biological approaches, in vivo mouse and zebrafish systems and analysis of human leukemia samples. He is also conducting discovery for cis-regulatory non-coding genomic elements associated with human leukemia and hematopoietic stem cells. His best known research accomplishment is the detection of point mutations in the RUNX1/AML1 gene in acute myeloid leukemia patients.