CCL2 and Alzheimer disease: QC and iso‐QC are involved in the post‐translational modification of Aẞ peptides into toxic pyroglutamate Aß and cytokine monocyte chemoattractant protein‐1 (CCL2) into neuroinflammatory pGlu‐CCL2, both of which are upregulated in AD (Feldman et al.