Ex vivo tumor uptake and tumor-to-blood ratio were higher for [89Zr]Zr-N-sucDf-NNV003 compared to [111In]In-DTPA-IgG (10.9 vs. 3.9%ID/g; P < 0.05 and 2.4 vs. 0.5; P < 0.01) (Fig. 2D), indicating [89Zr]Zr-N-sucDf-NNV003 tumor uptake is CD37-mediated. This evidence concerns the gene CD37 and neoplasm.