Kai-Keen Shiu, FRCP, PhD, University College London Hospitals NHS Foundation Trust, London, UK, discusses the importance of the results from KEYNOTE-177 (NCT02563002) for patients with bowel cancer, and their treating physicians, including the significance of determining whether tumors are microsatellite-instability high or mismatch repair deficient. This interview was recorded via an online conference call with The Video Journal of Oncology (VJOncology).