The rise of human stem cell-derived natural killer cells for cancer immunotherapy.

Introduction: Natural killer (NK) cell therapy has been proven to be safe and clinically effective for the treatment of multiple cancers, in particular blood cancers. Most of the clinical trials use primary NK cells from peripheral blood or umbilicalcord blood, or NK-92 cells. Each cell source is confined by limitations, such as donor dependence, low persistence in vivo, and its difficulty to genetically modify. Thus, there is an urgent need to explore novel NK cell sources for clinical use.Areas covered: This article highlights the recent progress in utilizing stem cell-derived NK cells as anticancer therapies and strategies to improve their antitumor activities.Expert commentary: Stem cell-derived NK cells are homogenous, easy to genetically modify on a clonal level, and can be expanded to clinical scale. They may therefore arise as an ideal population for developing off-the-shelf, standardized adoptive NK cell therapeutic products.