On the other hand, the tumor uptake of [64Cu]Cu-NOTA-EV-F(ab′)2 peaked at 4 h after injection (Fig. 2B), with values of 9.70 ± 0.65, 8.57 ± 0.49, and 4.40 ± 0.45 %ID/g in breast tumors with high, intermediate, and low nectin-4 expression, respectively. This evidence concerns the gene NECTIN4 and breast neoplasm.