To investigate the dependence of PSMA-I&F uptake in different mouse organs (tumor, kidney, spleen) on in vivo PSMA expression, PSMA immunohistochemistry was performed on tissue samples of LNCaP xenograft–bearing CB17 SCID mice, and immunohistochemistry data were compared with the results obtained by fluorescence microscopy of tissue cryosections 1 h after injection of PSMA-I&F in the same tumor model (Fig. 5). This evidence concerns the gene FOLH1 and neoplasm.