The livers of mice with acute hyperammonemia showed increased concentrations of glutamine, uridine and UDP-GlcNAc (Fig. 1b), while both protein amount (Fig. 1c, d) and catalytic activity (Supplementary Fig. 1a) of glutamine-fructose-6-phosphate aminotransferase 1 (GFPT1), the rate-limiting enzyme in HBP, were unaffected. The gene discussed is GFPT1; the disease is Hyperammonemia.