Glutamine transport across cell membranes is performed by a variety of transporters, including the alanine serine cysteine transporter 2 (ASCT2). The substrate-binding site of ASCT2 was proposed to be specific for small amino acids with neutral side chains, excluding basic substrates such as lysine. In this issue Ndaru and co-workers (pp. 1443–1457) expand the substrate specificity of ASCT2 to include amino acid substrates with positively charged side chains. The image shows the docking pose of L-DAB and L-DAP, from the side view of the ASCT2 homology model in the outward-open conformation.The image was provided by Christof Grewer.