Magnus Björkholm, MD, PhD, of the Karolinska Institute, Stockholm, Sweden, speaks at the International Symposium on Acute Leukemias (ISAL) 2019, held in Munich, Germany. He discusses key examples of where population-based registry studies have answered questions in the field of hematological oncology, including chronic lymphocytic leukemia, multiple myeloma and myeloproliferative neoplasms.