CTLA4 and neoplasm: The third is to improve the tumor immunosuppressive microenvironment by reprogramming or regulating the activity of immune cells, including T cells, TAMs, dendritic cells (DCs), etc. For example, the team of Prof. Fu et al. [50] had developed and detected a heterodimer that binds an anti-CTLA-4 antibody targeting regulatory T cells to a CD-47 ligand signal-regulatory protein, which could selectively block CD47 on intratumoral T cells, effectively remove immunosuppressive T cells in the TME, and significantly enhance the anti-tumor immune response.