Carsten U Niemann is an expert in clinical and laboratory hematology with more than 10 years hands-on experience in hematology research laboratories in Europe and US, heading the leukemia research laboratory and the clinical research program for CLL at Rigshospitalet, Copenhagen, Denmark. He has authored more than 70 research papers book chapters and reviews. Combining genetic and functional characterization of CLL and microenvironmental cells, MRD testing and diagnostics for CLL, along with epidemiological studies, he has impacted current practice in CLL, as evidenced by co-authorship on the updated ESMO guidelines, the current guidelines for TP53 mutational analysis in CLL and the guidelines on flowcytometric diagnosis of CLL. Based on combining studies of microenvironment in CLL and epidemiology with machine learning, his research group is focusing on all aspects of immune (dys)function in CLL. As chair of the Nordic CLL study group, he is founding member of the GAIA/CLL13 and Vision/HO141 clinical trials as well as the upcoming CLL17 and HO158 clinical trials along with having developed and being sponsor for the machine learning based PreVent-ACaLL clinical trial, thus leading the way for testing novel targeted and personalized therapy in CLL.