CDK8 and cancer: As aforementioned, pharmacological inhibition or knockdown experiments have suggested that CDK8 and CDK19 control different sets of target genes.165,358 Several CDK8 pharmacological inhibitors have been developed,171,359 which are expected also to target CDK19, however reducing the capability to discern between CDK8 and CDK19 unique functions in cancer and leading to high toxicities at therapeutic dose levels as dual inhibitors.360