CXCR4 and cholangiocarcinoma: Studies have showed that MSCs can promote tumour growth by migrating to the developing intrahepatic cholangiocarcinoma through SDF‐1α/CXCR4 signalling pathway 35, and MMP2 molecular factor in human medulloblastoma 36, in which subsequently may lead to the effects of angiogenesis via VEGF, MCP‐1 and HIF‐1 signalling pathways.