STAT3 and cancer: Similarly, research on fibrosarcoma and lung cancer cells showed that cancer cell-derived PAI-1 stimulates macrophage migration via its LRP1 binding domain and induces M2 polarization by activating the p38MAPK/NF-kB signaling pathway and the IL6/STAT3 autocrine loop through its C-terminal urokinase plasminogen activator (uPA) binding domain [32].