MAPT and tauopathy: In tauopathies, calcium homeostasis is dysregulated [83]; thus, researchers have shown interest in studying the calcium-dependent kinase Ca2+/calmodulin-dependent protein kinase II (CaMKII), which phosphorylates tau at residues located in microtubule-binding domains [84,85], resulting in the formation of fibrillar tau aggregates (PHFs and NFTs) in the hippocampus [62,86,87,88].