CCL2 and neuroblastoma: Upon interaction with NB cells, they release several pro-tumourigenic cytokines and chemokines, such as transforming growth factor (TGF)-β1, IL-6, IL-8 and macrophage chemoattractant protein-1 (MCP-1 a.k.a CCL-2) driving a Th-2 inflammatory reaction leading toward immune escape [18].