OPN is found in higher levels in the plasma of AD patients (Comi et al., 2010; Carecchio and Comi, 2011), is known to enhance bone resorption (Luukkonen et al., 2019), and reduces Aβ burden in murine models of AD (Rentsendorj et al., 2018). This evidence concerns the gene SPP1 and Alzheimer disease.