Jan Cools obtained his PhD degree in 2001 from the KU Leuven with a study on chromosomal defects in leukemia. From 2001 to 2003 he continued his research on the genetic causes of leukemia at Harvard Medical School (Boston, USA). After return to Belgium, he was promoted to assistant professor in 2005 and to full professor in 2009 at KU Leuven. In 2008, Jan was also appointed as group leader of VIB, a life sciences institute in Flanders. His research team studies the genetic complexity of acute lymphoblastic leukemia (ALL) and uses that information to develop novel models of leukemia development and novel treatment strategies. For these studies the team is now using single-cell DNA and RNA sequencing to unravel the heterogeneity of ALL at diagnosis and during chemotherapy treatment. He has served as a board member of the European Hematology Association and has been the editor-in-chief of the open access journal Haematologica from 2012 to 2017 and is now editor-in-chief of a new open access hematology journal: HemaSphere (journal of the European Hematology Association).