CCND1 and cervical squamous intraepithelial neoplasia: Significant differences were revealed in the levels of expression of OVCA1 and p16 compared to the norm in cervical cancer tissues and areas with CIN, between CIN and carcinoma tissues, and in the expression of the cyclin D1 protein in normal tissue and in the area of cervical cancer, and in the areas of CIN and cervical cancer, while not there was a significant difference in cyclin D1 expression levels between normal and CIN tissue.