(a) Reverse transcriptase PCR for HPV-16 E6, E7 and β -actin transcripts in OKF6 cells. (b) Immunofluorescence by confocal microscopy revealing E7 expression in OKF6 cells. (c) Left side: Western blot for p53 and pRb proteins in OKF6 cells. Right side: densitometric analysis. (d, e) Quantitative transcriptase-reverse PCR for p16 and hTERT transcripts in OKF6 cells that express HPV-16 E6 and E7. These results are representative of three independent experiments. ***: p<0.001.