Antitumor efficacy and safety were also evaluated <i>in vivo</i> using a tumor-bearing mouse model.<h4>Results</h4>Intratumoral <i>F.n</i> subverted antitumor immunity through a dual mechanism, coupling major histocompatibility complex class I (MHC-I) degradation with PD-L1 upregulation. Here, CD274 is linked to neoplasm.