CDK17 (Cyclin-dependent kinase 17): CDK17 is a nuclear enzyme belonging to the cyclin-dependent kinase family, which is essential for cell cycle regulation, transcriptional control, and cellular differentiation. Acting as a serine/threonine protein kinase, CDK17 phosphorylates target proteins to modulate their activity. It plays a key role in driving cell cycle progression, particularly in promoting the transition from the G1 phase to the S phase, where DNA replication occurs.