As shown in supplementary Fig. S14, we found that the therapeutic efficacy of local gel-released P-aPD-1 (0.1 mg/kg of aPD-1, single dose) was better than that of the systemic P-aPD-1 treatment (0.5 mg/kg of aPD-1, single dose), which could be attributed to the insufficient accumulation of P-aPD-1 at the tumor site at a relatively low dose (0.5 mg/kg of aPD-1) after systemic administration to trigger a robust immune response. Here, MTPAP is linked to neoplasm.