MYC and neoplasm: This notion is further supported by previous studies that in MYC-driven liver tumors GLS1 induction was accompanied by low level of GS, while in contrast, GS was elevated in MYC-driven lung tumors.45 Even in a single tumor cell, MYC may simultaneously promote both GS and GLS expression, as these two reactions occur at different subcellular compartments: glutaminolysis predominantly in mitochondria, whereas glutamine synthesis in the cytosol.