MAPT and Alzheimer disease: An increased level of plasmatic Cu unbound to ceruloplasmin (nCp-Cu, also known as “free copper”) was found to be correlated with brain atrophy, CSF levels of Aβ and p-tau, and more severe clinical courses in patients with AD (Squitti et al., 2006; Strozyk et al., 2009; Diouf et al., 2020).