SLC7A5 (LAT1), highly expressed in many, although not all, cancers (Fuchs and Bode, 2005; Kaira et al., 2008) transports mainly essential amino acids, is specific toward branched-chain- and bulky amino acids and the influx of one substrate is coupled with removal of another amino acid from the cell. The gene discussed is SLC7A5; the disease is cancer.