Notes: PNU 112455A is an inhibitor of cyclin-dependent kinase 2 (Cdk2) and Cdk5 (Ki = 2 µM for both).{63141} It inhibits hyperphosphorylation of tau and cell death induced by the synthetic glucocorticoid dexamethasone (Item No. 11015) in PC12 rat adrenal medulla cells expressing human tau when used at concentrations of 1 and 10 µM.{63142}