Niclosamide, a small-molecule STAT3 inhibitor, leads to a significant decrease in the protein levels of downstream anti-apoptotic target genes (such as Bcl-XL and survivin) by inhibiting Tyr-705 phosphorylation and nuclear translocation of STAT3, thereby improving the survival of patients with radioresistant breast cancer [142,143]. Here, STAT3 is linked to breast cancer.