In the current study, we found that false-positive LNs contained a significant number of MDSC (Fig. 3g) and expressed S100A8/A9 (Fig. 4b), and that tissue S100A8/A9 expression in the absence of cancer cells can induce significant 18F-FDG uptake in the injected tissue (Fig. 4a). Here, S100A8 is linked to cancer.