STAT3 and head and neck squamous cell carcinoma: In several types of HNSCC cells, STAT3 signaling has been reported to be activated by the RTK Family, alpha‐7 nicotine receptors, the interleukin family (IL‐6, IL‐10, and IL22 receptors), erythropoietin receptors, TLRs, GPCRs, TGF‐α activation, and circular RNA FAT1 (circFAT1).2, 51, 53, 54