Additionally, a syngeneic tumor model might compromise the efficacy of immune checkpoint inhibitors due to low homologies between human PD-1 and mouse PD-1; therefore, we evaluated the BsDb’s antitumor activity in vivo using a PD-L1 positive HT29 colon cancer xenograft mouse model based on many previous studies [39,40,41]. The gene discussed is CD274; the disease is malignant colon neoplasm.