Biomarker screening has become an essential component of constructing treatment plans in chronic lymphocytic leukemia (CLL). In this video, recorded at the 23rd Congress of the European Hematology Association (EHA) 2018, held in Stockholm, Sweden, Paolo Ghia, MD, of the Università Vita-Salute San Raffaele, Milan, Italy, discusses three key tests that he thinks are essential for the proper management of CLL. These tests examine the presence/absence of 17p deletions, and P53 mutations and Ig mutations. Dr Ghia demonstrates the importance of these tests by explaining what they can tell us about treatment. Patients with 17p deletions or P53 mutations will not benefit from immunochemotherapeutic treatments. Of these patients, those with Ig mutations should be given chemoimmunotherapy, but those without such mutations should be given novel agent therapies.