CDK5 and Alzheimer disease: With regard to AD it is interesting that Aβ was shown to activate CDK5 (Lee et al., 2000; Shukla et al., 2012) whereas this study indicates that APPsα rescues p25 hyperactivation, suggesting that an imbalance in non-amyloidogenic α-secretase processing versus β-/γ-secretase processing may lead to CDK5 dysregulation and contribute to pathological signaling cascades [see also review by Mockett et al. (2019)].