NECTIN4 and neoplasm: At the same time point, blocking experiments significantly reduced tumor uptake (5.23 ± 0.31%ID/g, P = 0.00074), while uptake in the H520 negative group was even lower (2.77 ± 0.47%ID/g, P = 0.00024), confirming the specificity of [64Cu]Cu-NOTA-EV-F(ab’)2 for Nectin-4 targeting.