Of note, APP/PS1 mice were characterized by increases in several distinctive markers of AD, such as: Carboxylic acids (a circulating marker of mitochondrial dysfunction) (28), deaminated purines (e.g., allantoate), glutaminolysis (glutamine, glutamate), glutathione turnover metabolites (5-oxoproline), proteolysis (including several free amino acids and urea cycle intermediates such as ornithine), and tryptophan catabolism (kynurenine) (Fig. 6 D–G). The gene discussed is APP; the disease is Alzheimer disease.