GLUD1 and metastatic malignant neoplasm: Ammonium supplementation induced either a small (HeLa, DU145) or large (MDA-MB-231) increase, or no change (Colo 205), in the total GDH (GDH1 + GDH2) protein content in metastatic cancer cells, and no change in non-metastatic (MCF-7) cells (Figure 3A).