TGFB1 and cancer: Interleukin-6 produced by triple-negative breast cancer tumor cells can activate the JAK2/STAT3 axis in tumor-associated macrophages, inducing the secretion of TGF-β1, which in turn activates the TGF-β1 pathway in tumor cells and regulates the expression of hepatocyte leukemia factor (HLF), a novel cancer protein.