CX3CR1 and neoplasm: Time‐of‐flight mass cytometry analysis revealed that R‐CM@MSN@BC can remodel the immunosuppressive tumor microenvironment by polarizing M1‐type macrophages, reducing infiltration of M2‐type and CX3CR1+ macrophages, and decreasing T cell exhaustion, thereby increasing the effectiveness of anti‐programmed cell death ligand 1 immunotherapy.