TIGIT and neoplasm: TIGIT blockade restored the ability of NK cells to produce IFNγ and TNFα and degranulate (based on CD107a surface expression) upon restimulation with PVR+ cells in tumor-exposed PM21-NK cells back to levels comparable to re-stimulation with PVR−-K562 cells, and for TNFα and degranulation to levels observed for unexposed NK cells stimulated with PVR+-K562 cells.