John Byrd, MD, Ohio State University, Columbus, OH, gives an overview of the use of biomarkers in the field of treatment of chronic lymphocytic leukemia (CLL), commenting on the impact of Bruton’s tyrosine kinase (BTK) inhibitors and the role of NOTCH mutations and Richter’s transformation. Dr Byrd also discusses the future role of biomarkers in the CLL space. This interview took place at the virtual European Hematology Association (EHA) Congress 2021.