Thus, PCNA can be regarded as a surrogate marker of viral early gene activity in papillomavirus infected tissue.18 Branca et al19 observed that in patients with cervical intraepithelial neoplasia (CIN) or cervical carcinomas PCNA expression intensity was significantly associated with the detection of high-risk HPV in the lesions, being significantly more intense in high-risk HPV positive lesions. Here, PCNA is linked to cervical intraepithelial neoplasia.