In addition, the enlarged tumor weight and tumor size were also observed in mice received 5-Fu treatment and overexpression of KCNQ1OT1 or XIST, compared to that only received 5-Fu treatment (Fig. 8D–F), indicating that KCNQ1OT1/XIST overexpression weakened the anti-tumor effect of 5-Fu in vivo and strengthened the drug resistance to 5-Fu in colorectal cancer. This evidence concerns the gene XIST and colorectal cancer.