CDK13/CHED

A close paralog of CDK12, CDK13 was earlier called CHED for its role in development. With cyclin K, it phosphorylates the RNA polymerase II CTD and sustains transcription of genes needed for organogenesis. De novo or inherited CDK13 variants cause a recognizable syndrome featuring congenital heart defects, neural tube defects, facial dysmorphism and developmental delay, and Cdk13 loss in mice impairs heart, gut and craniofacial development. CDK13 is expressed widely but enriched in developing tissues, and like CDK12 it carries C-terminal RS-domain features linking transcription to RNA processing. CDK12/CDK13 inhibitors are being evaluated in transcription-addicted cancers.