Recent studies support a role for CSPG abnormalities in Alzheimer’s disease, including PNN deficits, CSPG expression in amyloid beta plaques, decreased CSF levels of NG2, and increased levels of chondroitin-4-sulfate (Bruckner et al., 1999; Baig et al., 2005; Morawski et al., 2010; Lendvai et al., 2013; Nielsen et al., 2013, 2014; Vegh et al., 2014; Howell et al., 2015; Yang et al., 2017; Cattaud et al., 2018; Schultz et al., 2018). This evidence concerns the gene CSPG4 and early-onset autosomal dominant Alzheimer disease.