This one-day symposium was organized by 1st Faculty of Medicine, Charles University and the Institute of Hematology and Blood Transfusion, presenting two invited lectures, Michael Deininger, MD, PhD from University of Utah, Huntsman Cancer Institute, Salt Lake City and Eric Bouhassira, PhD from Albert Einstein College of Medicine, New York. Presented talk "Variation of gene expression during normal hematopoiesis" covered Clonal allele-specific analysis of gene expression, DNA methylation and DNA replication during normal hematopoiesis.