HGF and breast cancer: Utilizing STRING protein–protein interaction network analysis and their functional interpretation, the focus was directed towards cytokines SDF-1, LIF, VEGF, bFGF, HGF, and SCGF-β that are less frequently analyzed in the immunosuppressive tumor microenvironment, which form a unified signaling axis integrating angiogenesis, stem cell survival, immunoregulation, and microenvironmental remodeling in BC (Figure 8).