Scott Kopetz, MD, PhD, The University of Texas MD Anderson Cancer Center, Houston, TX, describes important requirements for circulating tumor cells (CTCs) to move forward in the pharmaceutical industry. This includes uncovering which patients CTC approaches should be examined on and whether there are a subset of patients that are insensitive to CTC methods. Additionally, Dr. Kopetz mentions the need for understanding the regulatory framework in this therapeutic area as well as more innovative trail design. This interview took place at the American Society of Clinical Oncology (ASCO) Gastrointestinal Cancers Symposium.