Figure 1. CTCF is significantly upregulated in CRC tissues and acts as a potential oncogenic gene. (A) CTCF is upregulated in all gastrointestinal tumors (GEPIA, http://gepia.cancer-pku.cn/). (B) Kaplan-Meier relapse free survival analysis in CRC patients with high or low expression of CTCF in GSE31598 via online website PROGgeneV2 (http://genomics.jefferson.edu/proggene/). (C) GSEA indicated that high expression of CTCF was positively correlated with the cancer related gene set signatures (KEGG_PATHWAYS_IN_CANCER, KEGG_COLORECTAL_CANCER) in CRC patient gene expression profiles (GSE17538, n = 177, and TCGA, n = 465). (D) qRT-PCR analysis of CTCF expression in 77 pairs of CRC patient specimens. (E) Western blot analyses of CTCF in 12 pairs of tumor and match adjacent normal tissues collected from clinical CRC patients. N for Normal, T for Tumor. The above data are presented as mean ± SEM. * P<0.05, **P<0.01, and ***P<0.001.