Given that Aβ and these two enzymes (partly in the form of BAβACs) coexist in CSF, and that the heaviest BAβACs represent the oldest complexes, it is expected that AChE activity is inhibited by Aβ in the oldest complexes, thereby the Ultra-heavy forms of BAβACs display a latent (inactivated) phenotype as is depicted in the AChE SDG spectra (Figure 4E), and to a lesser degree in the BuChE SDG spectra (Figure 4G) in AD CSF. The gene discussed is ACHE; the disease is Alzheimer disease.