PRC1 and cervical squamous intraepithelial neoplasia: According to the median and distribution of the data in the box plots, the 9 markers can be classified into 3 groups; the first group included markers linked exclusively (CCNB2, PRC1) or mostly (SYCP2) to invasion, which clearly differentiated invading tumors from high-grade CIN, low-grade CIN, and normal cervices.