NRXN3 and Alzheimer disease: The other proteins were elevated in the subjects with MCI-AD compared with the subjects with sMCI, with the largest effect sizes being for CHGA (β = 0.98 [SE 0.26]), NRXN-3 (β = 0.96 [SE 0.35]), and NFASC (β = 0.92 [SE 0.35]).