Neurodegenerative diseases are particularly challenging diseases, as they are difficult to diagnose in the initial stages. Although many years of research have been devoted to the identification of suitable biomarkers, preferably in blood, that would allow early diagnosis or even prediction of AD in humans, such markers remain elusive. Numerous candidates have been identified in both blood and CSF, but none of the markers identified so far have been used routinely in the clinics. CSF levels of Aβ, total TAU and hyperphosphorylated TAU are the most often monitored variables, along with PET molecular imaging of amyloid and TAU deposition, in diagnosis of early stages of AD (McKhann et al., 2011).