STAT3 and breast cancer: Our previous and other studies have shown that STAT3 promoted breast cancer cell migration, and MRTF-A and STAT3 synergistically increased MDA-MB-231 cell migration by promoting the expression of migration markers Myl-9, Cyr-61, urokinase-type plasminogen activator (uPA) and osteopontin (OPN) and inhibiting the expression of breast cancer metastasis suppressor 1 (BRMS1, [11, 12]).