CDK8 and prostate cancer: CDK19 elevation in AR-positive prostate cancers was confirmed at the protein level by Western blot analysis (Figure 1C), which compares CDK8, CDK19, and AR (including full-length AR [AR-FL] and AR variants [AR-Vs]) in different PCa cell lines (HEK293 [293] cells and 293 with knockout of both CDK8 and CDK19 [293-dKO] [ref. 34] were used as reference controls).