In in vivo studies, [18F]RPS-544 displayed a tumor uptake of 3.4 ± 1.2% ID/g at 1 h post-injection in the PC3-CXCR4 tumor and 1.1 ± 0.5% ID/g in the PC3-WT tumor. This evidence concerns the gene CXCR4 and neoplasm.