Among regioisomer and stereoisomer of α-methyl-phenylalanine tested, 2-[18F]fluoro-α-methyl-L-phenylalanine ([18F]FAMP) featured high tumor uptake via LAT1 (higher than [18F]FAMT) and low kidney accumulation (significantly less than [18F]FAMT). This evidence concerns the gene SLC7A5 and neoplasm.