Clemens Wendtner, MD from the University of Cologne, Cologne, Germany, discusses genetic risk factors for chronic lymphocytic leukemia (CLL) at the British Society for Haematology (BSH) Annual Scientific Meeting 2017 in Brighton, UK. He explains the differences in CLL prevalence between men and women, and speaks about the increased risk of relatives developing the disease in families with CLL. Prof. Wendtner also mentions the influence of environmental factors, and how these can interact with genetic risk factors.