TG2-L and TG2-S hemizygous CRND8 mice [31], and B6SJL transgenics [38], further enrich the genetic models used, while p25/Cdk5 hyperactivation [51], induced by removal of doxycycline in genetically modified mice, highlights another mechanism involving tauopathy. The gene discussed is CDK5; the disease is tauopathy.