HGF and neoplasm: Moreover, these stem cells can be attracted from the bone marrow and from the intestinal epithelium in response to tumor or injured tissue derived plasma chemo-atractants such as stromal derived factor-1 (SDF-1), vascular endothelial growth factor (VEGF), zonulin, hepatocyte growth factor (HGF) or shphingosine-1-phosphate (S1P), ceramides, and extracellular nucleotides [102,103].