LAMP2 and mucopolysaccharidosis type 2: In group C, the area of Lamp-2 immunostaining was smaller in the untreated MPS II mice compared with that of the untreated KO mice of group B. This can be explained by decreased Lamp-2 deposits due to the decreased neuronal density in the older KO mice of group C. There was no significant reduction of Lamp-2 immunostaining in any treatment group (Fig. 4c).