TIGIT and neoplasm: Compared to unexposed cells, A549 tumor exposure either in the presence of isotype control or anti-TIGIT antibodies did not result in a change in the frequency of TNFα+ NK cells induced in response to PVR−-K562 cell restimulation (27 ± 6% in the presence of isotype control and 30 ± 8% with anti-TIGIT antibodies) (Figure 6D).