Chimeric antigen receptor (CAR)-engineered T (CAR-T) cells have obtained prominent achievement in the clinical
immunotherapy of hematological malignant
tumors, leading to a rapid development of cellular
immunotherapy in
cancer treatment. Scientists are also aware of the prospective advantages of CAR engineering in cellular
immunotherapy. Due to various limitations such as the serious side effects of CAR-T
therapy, researchers began to investigate other immune cells for CAR modification. Natural killer (NK) cells are critical innate immune cells with the characteristic of non-specifically recognizing target cells and with the potential to become "off-the-shelf" products. In recent years, many preclinical studies on CAR-engineered NK (CAR-NK) cells have shown their remarkable efficacy in
cancer therapy and their superiority over autologous CAR-T cells. In this review, we summarize the generation, mechanisms of anti-
tumor activity and unique advantages of CAR-NK cells, and then analyze some challenges and recent clinical trials about CAR-NK cells
therapy. We believe that CAR-NK
therapy is a promising prospect for
cancer immunotherapy in the future.