Time-dependent accumulation of [89Zr]Zr-H4-Fc, [89Zr]Zr-H15-Fc and [89Zr]Zr-H17-Fc at FAP-expressing tumor sites was evident over the course of the 96-h study, while tumor localization of [89Zr]Zr-NGS2405-Fc rapidly plateaued within 24 h. This evidence concerns the gene FAP and neoplasm.