Brain metastatic cells are capable of triggering a phenotypic switch from normal astrocytes to tumour-associated astrocytes through the IL-1β-mediated NF-κB pathway, which, in turn, induces c-Met activation in tumour cells through the expression of hepatocellular growth factor (HGF), promoting survival and growth of brain metastatic cells [241]. This evidence concerns the gene HGF and neoplasm.