PDCD1 and neoplasm: This is supported by our studies in murine models of TNBC whereby response to anti-PD-1 relied on combination therapy with type I IFN inducers, promoting a long-term tumor-specific T-cell response.28,29,33 Together, these studies highlight type I IFNs as crucial regulators of the immunoreactivity of the TME and potential biomarkers of therapeutic response.