IDO1 and Stroke: In accord with changes of metabolite levels, activities of KP enzymes differed as well: IDO1, KMO, 3-hydroxyanthranilate 3,4-dioxygenase (3-HAO) and the composed 3-HAO and aminocarboxymuconate semialdehyde decarboxylase (ACMSD) activity was higher in stroke patients compared to controls [16].