Finally, consistent with our observations, type 1 interferons have been shown to induce PD-L1 expression on tumor cells and PD1 expression on immune cells in head and neck squamous cell carcinoma88 and to synergize with coated anti-CD3/28 antibodies in vitro to induce expression of co-inhibitory receptors such as Tim-3, Lag3, and PD189. This evidence concerns the gene PDCD1 and neoplasm.