A main focus of the research is molecular aberrations in MDS, with a particular focus on the pre-MDS phase. Patients are often referred with cytopenia, the cause of which remains unknown after standard diagnostic work up. These patients were previously followed for years with no definite diagnosis, however recent studies from the Grønbæk group and others show that around half of these patients have clonal hematopoiesis (i.e. clonal cytopenia of undetermined significance, CCUS). Although these mutated cells may be excellent candidates for being pre-cancer stem cells (CSCs) additional work is required to understand this. It is still unclear why some patients with CCUS develop overt MDS/AML, while others stay cytopenic with no disease progression for years. It is clear that additional mutations in classical tumor suppressors and oncogenes are generally required for disease progression; however, whether other factors such as germline genetics, immune mechanisms, and life style play a role is still unclear. Together with the other members of PTH and the van Andel Research Institute, Stand up to Cancer, Epigenetics Dream Team, the Grønbæk group is currently exploring these mechanisms, with a particular focus on whether the progression of CCUS can be prevented or postponed. Our first studies focus on the role of vitamin C and its potential for rescuing TET2 deficiency, which we are currently perusing in clinical/translational trials.