Natural born killers: NK cells in cancer therapy

Chimeric antigen receptor-modified T (CAR-T) cells have brought a major breakthrough in tumor immunotherapy. As research continues to develop, CAR-T therapies have shown certain limitations, such as graft-versus-host reaction and the long time required to generate CAR-T cells. Natural killer (NK) cells, as the first line of defense against pathogens and cancer cells, belong to the innate immune system and have the advantage of being able to replace T cells, and can be used to prepare engineered chimeric antigen receptor-modified NK (CAR-NK) cells. The biological characteristics of CAR-NK cells, their sources, and the latest research progress and prospects for tumor treatment in China and worldwide are presented in this review.