Natural killer cells: from bench to cancer therapy

Natural killer (NK) cells are effectors of the innate immune system that play an important role in host response against viruses and tumour cells through the production of cytokines and direct cytolytic activity. There has been limited success reported from clinical trials in cancer patients treated with activated NK cells. Over the last decade, a better understanding of the biology of NK cells, NK cell receptors and the role of interleukin-15 has led to the development of new strategies using NK cells as immunotherapy for cancer treatment in the transplant and non-transplant settings.