Figure 1.

Progression of cervical cancer by HPV and promoter methylation during progression. Adapted from Woodman et al., 2007 [5]. The HPV virus has access to the basal cells by means of microlesions present in the cervical tissue. The virus is maintained in episomic form with a low number of copies (cells with a purple nucleus). The cells of the basal layer are divided and begin to migrate towards the surface. The untreated lesions progress to microinvasive and invasive cancer, where the HPV genome is associated with the host genome (cells with red nuclei). In the superficial layer the viral DNA is packed in capsids and the progeny is released to reinitiate the infection.