STAT3 and neoplasm: EMT is a fundamental process in the tumorigenesis, which confers malignant properties of tumor cells in invasion and drug resistance through the activated TGF‐β/Smads, Wnt/β‐catenin, Phosphatidylinositide 3‐kinases/protein kinase B (PI3K/AKT) and IL‐6/Signal Transducer and Activator of Transcription 3 (STAT3) pathways [16, 17].