There are several glutamine exchangers (ASCTs and Na+-coupled neutral amino acid transporters (SNATs)) that are often overexpressed by tumor cells (e.g., ASCT2 — SLC1A5; SNAT1 — SLC38A1, SNAT2 — SLC38A, and SNAT5 — SLC38A5) [164]. This evidence concerns the gene SLC1A5 and neoplasm.