We are continually learning new facts about the molecular basis of acute lymphoblastic leukemia (ALL) and how it is evolving. In this insightful interview, Bijal Shah, MD, of the H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, explains his thoughts on the topic. Dr Shah gives his perspective on the molecular subtypes of ALL, and the struggle of defining and detecting these, particularly without proprietary molecular profiling methods. He highlights the need to reach a consensus on definitions, terminology and detectiong, explaining how this would improve treatment. This video was recorded at the 1st International Workshop on Acute Leukemias (iwAL), held in St. Pete Beach, FL.