V-9302 hydrochloride is a potent and selective competitive antagonist that inhibits transmembrane glutamine flux by specifically targeting the amino acid transporter ASCT2 (SLC1A5), and not ASCT1. In HEK-293 cells, V-9302 hydrochloride effectively inhibits ASCT2-mediated glutamine uptake with an IC50 value of 9.6 μM.