Heinz Josef Lenz, MD, FACP, University of Southern California (USC), Los Angeles, CA, compares liquid biopsy to traditional clinical and pathological diagnosis technologies, such as tissue biopsy. A key advantage for liquid biopsy is that the method is highly suitable for addressing tumor heterogeneity, while a key disadvantage is that liquid biopsy can be limited in terms of the panel of genes that can be tested. Prof. Lenz highlights the range of new liquid biopsy technologies on the horizon. This interview took place at the International Society of Liquid Biopsy (ISLB) 2021 Virtual Meeting.