Compared with wild-type mice, 8-month-old MPS II mice showed strong colocalization of NeuN and LAMP1 in the cortex, striatum, hippocampus, and hypothalamus, with increased LAMP1 levels indicating a significant lysosomal burden in neurons (Fig. 5a–c). The gene discussed is RBFOX3; the disease is mucopolysaccharidosis type 2.