CTLA4 and neoplasm: ICB (immune checkpoint blockers) act on T‐cell immunosuppressive targets such as CTLA‐4(Cytotoxic T lymphocyte‐associated antigen‐4), PD‐1(Programmed cell death protein 1), or block immunocheckpoint‐related ligands such as PD‐L1(Programmed cell death ligand 1), bringing hope to patients with refractory tumors,1 as an important means of tumor immunotherapy, it can significantly improve the prognosis of tumor patients.