SLC7A5, L-type amino acid transporter 1 (LAT1), forms as a heterodimeric complex with the heavy chain of the cell surface antigen 4F2 (4F2hc/CD98). It transports neutral amino acids, most of which are essential amino acids across blood brain barrier. L-dopa, which is commonly used to treat Parkinson’s disease, also enters the brain the LAT1/CD98 complex. In addition, tumors with increased expression of SLC7A5 have been reported. Increased uptake of amino acids through SLC7A5 may facilitate tumor cell growth and survival.