SLC6A1 and Alzheimer disease: Notably, linear regression analysis revealed that there was a significant positive association between Hevin levels and the expression of all the identified synaptic components (Figure 6C, Data S2), highlighting the expression of GABA transporter Slc6a1 (r2 = 0.45 for controls; 0.41 for AD and 0,62 for MCI, p < 0.0001) and cytoskeletal dynamics regulator Cyfip1 (r2 = 0.56 for controls and 0.28 for AD; Figure S4C).