ADPGK and colon carcinoma: As for the choice of antigen, we employed Adpgk peptide which is a neoantigen identified in murine MC38 colon carcinoma.[3b] Specifically, the primary amine of PEI was grafted with the cross‐linker to create pyridyldithiol functional groups to which CSS‐Adpgk was conjugated to form PEI–Adpgk via disulfide linkage.