Jeffrey S. Miller, MD, University of Minnesota, Minneapolis, MN, discusses the impact of hypoxia on natural killer (NK) cells and explains how this impacts their therapeutic potential. Hypoxia is an important factor in the solid tumor microenvironment and experiments have shown that hypoxic conditions change the function of NK cells. This interview took place during the 36th Society for Immunotherapy of Cancer (SITC) Annual Meeting in Washington, D.C.