SLC1A5 and neoplasm: Many amino acid transporters have already been identified, and four types of amino acid transporters, L-type amino acid transporter 1 (LAT1, also known as SLC7A5) [4], sodium- and chloride-dependent neutral and basic amino acid transporter B(0 +) (ATB0,+, also known as SLC6A14) [5], alanine serine cysteine transporter 2 (ASCT2, also known as SLC1A5) [6], and cystine/glutamate transporter (xCT, also known as SLC7A11) [7], are reportedly highly expressed in tumor cells (Table 1).