In contrast to the single knockouts,double knockout clones were completely unresponsive to CCT251921 treatment(T/C: 113 ± 10%, p < 0.005; Figure A), demonstrating that inhibitionof both CDK8 and CDK19 is required to slow or arrest growth in theSW620 colon cancer xenograft model. This evidence concerns the gene CDK8 and colonic neoplasm.