CDK8 is recruited to the viral genome upon differentiation. ChIP was performed using non-specific IgG or antibodies specific for CDK8 (a, b) or MED1 (c) on chromatin from HPV16 cells grown in monolayer or MC for 24 hours. qPCR was performed on the ChIP products using primers specific for the p670 region (a, c), the E1 region (a), the E5 region (a), or the central LCR (b, c). Ct values were normalized first to input and then to the IgG control for each experiment. Values represent means of 3 (a), 6 (b), or 3 (c) experiments and bars represent ± one standard error of the mean. *=p<0.05, ***=p<0.01, NS=p>0.05.