STAT3 and neoplasm: It was shown that STAT3 could promote tumor metastasis by regulating genes involved in the metastatic process, including down‐regulating E‐cadherin to facilitate the loss of cell to cell contact, up‐regulating Wiskott–Aldrich syndrome protein family member 3 (WASF3) to facilitate actin cytoskeleton reorganization, and regulating a variety of growth factors and cytokines 21.