Our study aimed to develop and evaluate [64Cu]Cu-NOTA-EV-F(ab′)2 for immuno-PET imaging of nectin-4 expression in triple-negative breast cancer (TNBC) and urothelial bladder cancer (UBC) models, with the goal of achieving rapid, specific tumor targeting and high tumor-to-background contrast. The gene discussed is NECTIN4; the disease is neoplasm.