SLC1A5 and lung cancer: Indeed, while we did not observe any specific correlation between GGT expression and ASCT2 levels in a group of seven cell lines analyzed, including human liver cancer cells (HepG2, Huh6), multiple myeloma cells (OPM2, JJN3, RPMI 8226), lung cancer cells (A549) and immortalized human bronchial epithelial cells (BEAS-2B) (see Supplementary Fig. S6), we also demonstrated the lack of any direct or inverse correlation between GGT expression or ASCT2 levels and GPNA/PNA sensitivity (see Supplementary Table S1).