AR and posterior cortical atrophy: These results indicate that downregulation of CDK8 and upregulation of CDK19 in primary PCa stem from the differential effects of androgen signaling on the expression of these genes and that the switch from canonical to non-canonical AR signaling in CRPC abrogates the negative regulation of CDK8 expression, allowing an increase in both Mediator kinases and their interactive proteins in mCRPC.