GPNA hydrochloride (L-γ-glutamyl-p-nitroanilide hydrochloride) is a substrate of γ-glutamyltransferase (GGT) and an inhibitor of the glutamine transporter ASCT2 with an IC50 of ~250 μM in A549 cells. It also inhibits Na+-dependent carriers SNAT1, -2, -4, -5 and Na+-independent leucine transporters LAT1/2. It can be widely used in research on pancreatic cancer, breast cancer, glioblastoma multiforme, acute myelogenous leukemia, and non-small-cell lung cancer.