Analysis of expression of EGFP, used as a control for transfection efficiency.

<p>Expression of EGFP was detected in all cells cotransfected with E7 genes and an EGFP expression construct. All transfections were done in duplicate. The amount of protein expressed declined with increasing numbers of optimized codons in the E7 genes suggesting down regulation due to expression of E7 (p<0.05, unpaired student t test).