In CD133-positive HCC stem cells, NTS stimulates and increases the expression and production of interleukin (IL)-8 and chemokine (C-X-C motif) ligand 1 (CXCL1), through activation of the RAF-1/ERK1/2 pathways, resulting in the building of the autocrine IL-8 signaling loop which promotes tumor angiogenesis, tumorigenesis and the self-renewal abilities of HCC cells77. The gene discussed is RAF1; the disease is hepatocellular carcinoma.