TGFB1 and hepatocellular carcinoma: Directional signaling flux analysis (COMMOT algorithm) further demonstrated the spatial polarization of vascular endothelial growth factor (VEGF) and TGF-β pathways: VEGF signals accumulated within the tumor regions of HCC-1L, whereas TGF-β signals originated from stromal compartments and converged onto the tumor regions in HCC-3L (Figures 6I and 6J).