JJ Schuringa heads the Department of Experimental Hematology at the University Medical Center Groningen and our aims are are to obtain detailed knowledge on (molecular) mechanisms that determine human hematopoietic stem cell self-renewal and differentiation, with the ultimate goal to deepen our insights in the development of human leukemias. We have a specific interest in dissecting the clonal heterogeneity of leukemias and recently developed tools that allow us to identify and prospectively isolate genetically distinct clones within individual patients. We perform gene-function analyses in both healthy and malignant human hematopoietic stem and progenitor cells in vitro and in vivo in our humanized niche xenograft leukemia clinic.