MAPT and Alzheimer disease: Importantly, alterations in the levels and phosphorylation status of p27(Kip1) have been observed in AD with excessive Aβ42 production, tau hyper phosphorylation and deregulated insulin signalling leading to an imbalance between the levels and functions of p27(Kip1) in the cytoplasm and nucleus by causing alterations in p27(Kip1) post-transcriptional modifications, which eventually leads to an aberrant cell cycle re-entry [131].