VGF and proteostasis deficiencies: A study found that in AD patients, brain-derived EVs increase the levels of hallmark proteins β-amyloid and tau and glial-specific molecules such as ANXA5, VGF, GPM6A, and ACTZ.369 In body fluid samples from AD patients, the combination of β-amyloid proteins, tau, and proteins unique to brain cells, such as ANAX5, VGF, GPM6A, or ACTZ, may be an applicant for a biomarker.365 Several neurological conditions are protein misfolding disorders, with evidence of harmful proteins spreading within the CNS.