Strategies to enhance tumor-to-background ratio include the use of smaller antibody fragments or peptide-based PD-L1-targeting ligands, which clear more rapidly from non-target tissues, like minibodies [6], nanobodies [7], monobodies (adnectines) [8] and affibodies [9] radiolabeled with, e.g., copper-64, gallium-68, zirconium-89 or fluorine-18 for PD-L1 PET imaging [10]. The gene discussed is CD274; the disease is neoplasm.