SLC7A5 and neoplasm: Inspired by [18F]FET, a para-fluoroethyl of alkylated phenylalanine, p-(2-[18F]fluoroethyl)-L-phenylalanine ((S)-4-[18F]FELP) was successfully synthesized (>95% radiochemical purity, up to 37% yield, and up to 69 GBq/μmol specific activity within 90 min) and showed LAT1-selective uptake in animal tumor models 116.