This model identified four proteins (secreted modular calcium-binding protein 1 (SMOC1), noggin (NOG), amyloid P component, serum (APCS), and netrin-1 (NTN1)) based upon the significance of feature frequency, among which SMOC1 displayed a positive feature coefficient—i.e., an increased level of this protein was associated with an increased probability of classification as AD (Supplementary Fig. 1a). This evidence concerns the gene NTN1 and Alzheimer disease.