STAT3 and breast cancer: Furthermore, it has been demonstrated that signal transducer and activator of transcription 3 (STAT3) promotes the production of angiopoetin-like 4 (ANGPTL4), matrix metalloproteinase 13 (MMP13), and stanniocalcin-1 (STC1) by fibroblasts associated with the disease, which in turn promotes the growth of BC [31].