SLC38A7 and cancer: To date, four distinct amino acid transporters have received increasing attention for their role in the promotion of cancer: SLC1A5 (also known as ASCT2), SLC7A5 (also known as LAT1), SLC7A11 (also known as xc−), and SLC6A14 (also known as ATB0,+) [46,47,48,49,50].