FIGURE 6.

Schematic of STAT3 signaling inhibitors. The principle of STAT3 inhibitors in tumor treatment is based on targeting upstream proteins of the STAT3 signaling or directly targeting STAT3; inhibition of upstream cytokine such as IL‐6 and tyrosine kinases JAK with small‐molecule inhibitors and natural compound such as tocilizumab, siltuximab, curcumin, ruxolitinib. As for inhibiting STAT3 in direct way, NH2‐terminal, DNA‐binding and SH2 domains can be targeted with OPB‐51602, S3I‐201, STAT3 decoy, G‐quartet oligodeoxynucleotide, AZD9150. Negative regulators of STAT3 can also play a role as STAT3 inhibitors (Figure 3)