In this work, to evaluate the antitumor effects of combined ST80 treatment in combination with an FDA-approved anti-hPD-L1 antibody (i.e., durvalumab), we have utilized a mouse orthotopic tumor model of 4T1-hPD-L1, where the basal mouse PD-L1 gene was replaced with a functional human counterpart. Here, CD274 is linked to neoplasm.