Intβ4f/f and K14CreIntβ4f/f mice reproductive tracts (N=6) were challenged with or without 3E+06 PVs (HPV16:LucF) as indicated. 48 hours after infection, mouse female reproductive tracts were harvested, protein lysates made, and luciferase assays were carried out to quantify the infectivity. Concentrations of total proteins were measure by Bradford protein assay. The infectivity level (relative luminescence units, RLU / µg) of Intβ4f/f mice treated with 3E+06 PVs was set as 100%. * P = 0.04 (Wilcoxon rank sum test, 2 sided).