Cyclin dependent kinase 5—a novel target to enhance the antitumor immune response

Cyclin dependent kinase 5 (Cdk5) is a serine/threonine kinase that has initially been discovered in the neuronal system and is essential for CNS development and function (1). During recent years, important functions of Cdk5 in various tumors have been elucidated and the genetic knockdown of Cdk5 as well as the inhibition of its kinase activity by small molecules has shown potent anti-cancer effects (2-5). Therefore, Cdk5 has emerged as a promising target for anti-cancer therapy.