Over the past few years, increasing evidence has shown that NIC displays multifunctional pharmaceutical activities and therapeutic prospects (Figure 2), including anti-cancer activity, metabolic regulatory activity [27], immunotherapeutic activity, and anti-viral and anti-bacterial activities [28], which can regulate multiple signaling pathways and biological processes [29], such as the Wnt/β-catenin [30], mTOR [31], STAT3 [32], NF-κB [33], and Notch signaling pathways [34]. This evidence concerns the gene STAT3 and cancer.