The article discusses research conducted by X. Wang and colleagues, which aims to analyze sorting nexin 27 (SNX27) gene and protein levels in individuals with learning and memory impairments. It reports how overexpression of human chromosome 21-encoded microRNA may be related to decreased SNX27 gene expression, endosomal protein sorting disruption, and glutamate receptor expression reduction. The reduced SNX27 levels in a person with Down's syndrome is also noted.