IFN-κ is suppressed in an E5-dependent manner. HPV16-containing and E5 Stop cells were isolated, and their RNA or protein was harvested. (a) Levels of IFNA and IFNB mRNAs were measured by RT-qPCR. (b and c) IFNK mRNA (b) and IFN-κ protein (c) levels were measured by RT-qPCR and immunoblotting, respectively. Levels of E7 were also measured by immunoblotting. (d) Quantification of immunoblots. n > 5 for all PCRs, and n > 3 for Western blots. *, P < 0.05; **, P < 0.01; ***, P < 0.001. The error bars indicate standard error of the mean.