STAT3 and inflammatory bowel disease: In IBD, the expression levels of IL-6/soluble IL-6 receptor (sIL-6R) complexes are increased, which in turn mediate the activation of signal transducer and activator of transcription-3 (STAT3); as a result, the IL-6/STAT3 pathway can stimulate the proliferation of premalignant intestinal epithelial cells, thereby promoting tumorigenesis (Francescone et al., 2015; Luo and Zhang, 2017).