Cyclin-dependent kinases: a family portrait

To the Editor, Cyclin-dependent kinases (CDKs) are protein kinases involved in critical cellular processes, such as cell cycle or transcription, whose activity requires association with specific cyclin subunits. Based on sequence similarity, the human genome contains 21 genes encoding CDKs and five additional genes encoding a more distant group of proteins known as CDK-like (CDKL) kinases. The current nomenclature for CDK proteins includes 11...