Fig. 3

Expression of HPV E1^E4 gene. a Copy number of the E1^E4 gene in specimens with different CIN grades. Statistical analysis was performed using a Steel–Dwass test. ** indicates p < 0.01. b Copy number of the E1^E4 gene in specimens with HPV16, 18, 52, and 58 infection. Statistical analysis was performed using a Steel–Dwass test. * indicates normalized copy number. ** indicates p < 0.01. c Detection rate of E1^E4 gene in each genotype stratified by CIN grade. Statistical analysis was performed using a Cochran-Armitage test