CD68 and early-onset autosomal dominant Alzheimer disease: Up-regulated CD68 expression in microglia has also been observed in various kinds of neurological diseases, such as Parkinson’s disease, Alzheimer’s disease, Pelizaeus-Merzbacher disease and brain tumor, which involves in neurodegeneration, neuronal death and neuroinflammation (Aronica et al., 2005; Bachstetter et al., 2013; Bachstetter et al., 2015; Aono et al., 2017).