Proteins OX-40 ligand (OX-40 L/TNFSF4/CD134L/CD252) and 4-1BB ligand (4-1BBL/TNFSF9/CD137L) regulate effector cytotoxic T-cell (CTL) activity while programmed death ligand-1 (PD-L1) exhibits immunosuppressive effects, allowing the tumor to escape immune destruction [55]. Here, TNFSF9 is linked to neoplasm.