Several of these transcripts were abundant and are known to play a role in brain function, including for example cystatin C (Cst3), the LDL receptor related protein 1 (Lrp1), which is downregulated in the brain of patients with Alzheimer's disease, the glucose-6-phosphate isomerase (Gpi), which promotes neuron survival, and the acyl-CoA synthetase long chain family member 3 (Acsl3), which encodes a protein involved in lipid biosynthesis and fatty acid degradation and known to be highly expressed in the brain. This evidence concerns the gene CST3 and early-onset autosomal dominant Alzheimer disease.