BDNF and Alzheimer disease: Collectively, these results show pervasive transcript-level decorrelation among top NPTX2 correlates in AD, with gene-specific behavior at the protein layer: BDNF and VGF maintained their correlations with NPTX2 across groups at both layers; SST and SERTM1 display modest over-correlating; SCG2 weakens across layers; and DUSP4/EGR4 lose transcript– NPTX2 protein correspondence.