PPT1 and adult neuronal ceroid lipofuscinosis: In addition, two different brain regions from three terminal AD-ANCL patients revealed significant secondary elevations (p ≤ 0.01) in the activity of the lysosomal enzymes palmitoyl-protein thioesterase 1 (PPT-1), β-glucuronidase (β-gluc,), and β-hexosaminidase (β-Hexa) (Fig. 1B).