Here, a pH-responsive lung metastatic-targetedcatalyst containing the tumor penetration polymer (TP)/solid lipids(SL)-coated Prussian blue (TP-SL@PB)-enhanced PD-L1 siRNA deliveryand self-cascade antigen capture is developed for reprogramming immunodeficiency.Intravenously injected TP-SL@PB accumulated in the blood vessel-poorlung metastases via the organ-selective targeting and charge conversionof TP. Here, CD274 is linked to neoplasm.