Endogenous role and harnessing possibilities of NK cells in cancer and beyond. NK cells are well recognized for their capacity to detect and eliminate tumor cells. Several strategies to harness these functions have been developed and are currently being evaluated in clinical trials for both hematologic malignancies and solid tumors. These advances are now being extended to investigate the potential of NK cell manipulation in other clinical contexts, including viral infections, neurodegenerative disorders, AIDs, and solid organ transplantation.