Your Outlook supplement on cancer immunotherapy (Nature 504, S1–S17; 2013) focuses mainly on T cells as a promising immunotherapy tool. But natural killer (NK) cells, another type of immune cell, may also be suitable for treatment of some cancers and are currently being tested in clinical trials (see, for example, A. M. James et al. Front. Immunol. 4, 481; 2013, and M. Cheng et al. Cell. Mol. Immunol. 10, 230–252; 2013).

Unlike T cells, NK cells are not directly antigen-specific. However, they can use an antibody-dependent mechanism to kill tumour cells: the antigen-specific fragment of these antibodies recognizes molecules on the tumour-cell surface, which activates the NK-cell cytolytic machinery.

Another approach is to use antibodies that suppress the tumour-induced inhibition of NK cells. Also, anti-cancer agents such as lenalidomide act in part by modulating NK-cell function.