The importance of this inflammatory ability of OVs has been given further weight by recent data showing that the early recruitment of particular innate immune cells is critical to initiate an anti-tumor immune response and subsequent response to immune checkpoint inhibitors.45, 46, 47, 48 In particular, NK-sDC interactions that exist in special anatomical locations within tumors are uniquely associated with responsiveness to anti-PD-1 immunotherapy.48 This evidence concerns the gene PDCD1 and neoplasm.