The increased uptake of amino acids such as O-(2-[18F]fluoroethyl)-l-tyrosine (FET) by glioma compared with healthy brain parenchyma seems to be caused predominantly by increased transport of large neutral amino acids through the plasma membrane via the l-type amino acid transporter (LAT) system, especially by the subtypes LAT1 and LAT2 [13]. This evidence concerns the gene LAT and central nervous system cancer.