In this study, we evaluated the value of p16INK4a immunostaining, as well as cytology and colposcopy, for predicting high-grade squamous intraepithelial lesions (HSIL) in human papillomavirus (HPV)-negative patients by comparing the methods with the haematoxylin and eosin (H&E) staining pathological diagnosis of HPV-negative patients. The gene discussed is CDKN2A; the disease is squamous cell intraepithelial neoplasia.