PAPPA and Alzheimer disease: The authors found that CSF levels of Al positively correlated with levels of phosphorylated tau isoforms, visinin-like protein 1 (VILIP-1), a neuronal calcium sensor protein, pregnancy-associated plasma protein A (PAPP-A), a marker of oxidative stress [75], and albumin, which may augment the risk of AD by inducing Aβ accumulation [76], thus providing relevant insights into the role of toxic metals in AD risk [48].