When new drugs are being tested as a treatment for a cancer, they are typically trialled in combination with standard chemotherapy. Here, Miguel Sanz, MD, of University Hospital La Fe, Valencia, Spain, explores why this is the case, and touches upon a notable exception to this tendency in the therapy of acute promyelocytic leukemia (APL). This video was recorded at the International Conference on Acute Myeloid Leukaemia 2017 in Estoril, Portugal by the European School of Hematology (ESH).