SLC6A1 and Alzheimer disease: PPI analysis on overlapping genes displayed several key hub genes, including CAMK2A (a critical kinase for synaptic plasticity), SLC6A1 (a GABA transporter), GRIA4 (an AMPA receptor subunit), and STMN2 (a regulator of microtubule dynamics), which formed a network of 21 nodes and 15 edges (Figure 4D), suggesting their potential collective role in mediating region-specific ExN dysfunction in AD.