CHRNA7 and Alzheimer disease: Hence, we explored whether the elevated Aβ42-α7nAChR complex levels and the magnitude of reduction by exogenous Aβ42 in promoting the Aβ42-α7nAChR association (reflected by +Aβ2/-Aβ42 ratios) may be used as AD diagnostic biomarkers that depict the severity of AD pathologies.