HGF and plasma cell myeloma: There is an extensive crosstalk between the BM stromal cells (BMSCs), BM endothelial cells and the MM cells which leads to the secretion of cytokines like hepatocyte growth factor (HGF), vascular endothelial growth factor, transforming growth factor-β, stromal cell-derived factor-1α (SDF-1α) among others that promote myeloma cell survival23.