Chronic lymphocytic leukemia (CLL) patients with a complex karyotype have poorer outcomes than those without these features; further analysis of these complex cases may improve our understanding of how to effectively treat them. Here, Blanca Espinet, PhD, of the Hospital del Mar Institute of Medical Research, Barcelona, Spain, discusses the cell-intrinsic biomarkers available for CLL, focusing on cytogenetics, and how these could affect the management of the disease. Notably, she highlights how certain groups of complex karyotypes may have better outcomes, so it is also important to be aware of these. This interview took place at the European Research Initiative on CLL (ERIC) International Meeting 2018, held in Barcelona, Spain.