Ng CSF levels were higher in subjects with AD (418±142 pg/ml; Fig. 2E) compared to subjects with NeuroDegen diseases (248±133 pg/ml; p<0.0001), NeuroCtrls (367±270 pg/ml; p<0.02), and HC (264±111 pg/ml; p<0.01). This evidence concerns the gene NRGN and Alzheimer disease.