CD274 and neoplasm: Across all four exogenous tumor models, [18F]FAC uptake in the TDLNs (brachial or axillary) was significantly higher in mice treated with anti-PD-L1 mAbs compared to isotype mAb controls, irrespective of tumor sensitivity to CIT (anti-PD-L1 mAb groups: 3–4.5%ID/cc, isotype mAb control group: 2–3%ID/cc; Fig. 2a–c).