CDK5 and Alzheimer disease: Previous results including our study in the CM-STZ injected non-human primate AD brain showed various cases of STZ-mediated changes in CDK5, p35, and p25 levels (Clodfelder-Miller et al., 2006; Chen et al., 2013; Park S. J. et al., 2015; Gratuze et al., 2017).