CDK8 and prostate cancer: On the other hand, a substantial fraction (close to 5%) of prostate cancers that did not belong to these two subtypes showed deep deletions of CDK8/CDK19/CCNC, suggesting that such deletions may indicate a particular subtype of prostate cancers where the Mediator kinase plays the opposite role to its carcinogenesis-associated effects in the majority of these tumors.