Constantine Tam, MBBS (Hons), MD, FRACP, FRCPA, The Peter MacCallum Cancer Centre, Melbourne, Australia, discusses data he has recently presented on circulating tumor DNA (ctDNA), and the utility of this technique in patients with Chronic Lymphocytic Leukemia (CLL) and Mantle Cell Lymphoma treated with ibrutinib or venetoclax. This interview was recorded via an online conference call with The Video Journal of Hematological Oncology (VJHemOnc).