Measurement of relative-fold increase (RFI): FA modulation of HPV effects. Analysis of RFI in CAL27 cells revealed the growth stimulating effects of HPV16, HPV18, FA  and FA  are reduced or inhibited when HPV and FA are concomitantly administered. Similarly, SCC15 cell growth stimulated by HPV18, FA [100 μg/mL] and FA [400 μg/mL] is either reduced or inhibited by concomitant HPV and FA administration. SCC25 cell growth, stimulated by HPV16, FA [100 μg/mL] and FA [400 μg/mL] is also significantly reduced, although not completely inhibited by concomitant HPV and FA administration. HGF-1 cell growth, stimulated by HPV16 and HPV18 but not FA administration, was robustly enhanced by concomitant administration of HPV and FA. Both HPV16 and HPV18 enhanced HGF-1 proliferation at either concentration of FA [100 or 400 μg/mL].