PTGS2 and cholangiocarcinoma: We analysed gene expression levels of NF-kB, COX-2, PI3K and PTEN from the CC group and control groups, the expression levels of NF-kB, COX-2, and PI3K were significantly overexpressed in all the cervical tissue biopsies while the expression of PTEN was noticeably decreased in all the cervical cancer tissue samples (Fig. 2A), housekeeping gene β-actin was used for the normalization gene expression.