HPV-11 mRNA expression patterns in specimens with HPV-11 infection. (a) Viral mRNA expression patterns in individual cases. E, epiglottis; NA, not available; NP, nasopharyngeal papilloma; PW, posterior wall of the hypopharynx; SP, septal exophytic papilloma; TVC, true vocal cord. E4, E5b, and E5a mRNAs were predominantly expressed compared with the other mRNAs in all subsites with HPV-11 infection. (b) Proportion of mRNA expression. The probability values (p) of the Kruskal–Wallis test were < 0.0001. Values with different characters (a, b, c, d, and cd in Figure 3b) are significantly different among the viral mRNAs (p < 0.05, Dwass–Steel–Critchlow–Fligner multiple comparison tests). E4, E5a, and E5b expression together accounted for 88%, while that of E6, E7, E1, E2, L2, and L1 was only 12%.