CTLA4 and neoplasm: Moreover, coupled with the blockade of immune checkpoints (anti-CTLA-4 antibodies) and the administration of immunostimulatory CpG oligonucleotide, this hydrogel-mediated localized radiotherapy not only targeted and eradicated metastatic tumors but also promoted an immune memory effect, offering a strategic avenue to prevent tumor relapse (Fig. 11j–l).654