Newer treatments for hematological malignancies, including immunotherapies and cellular therapies, are more targeted than historical chemotherapies. This means that the presence of the specific target is critical for the treatment to be efficacious. Speaking from the 3rd congress of European Hematology Association (EHA) 2018, held in Stockholm, Sweden, Ola Landgren, MD, PhD, from Memorial Sloan Kettering Cancer Center, NY, discusses the predictive biomarkers that can be used to aid treatment decisions. He also comments on the potential reasons for the different responses between patients with the same biomarkers treated with the same drug.