CCL2 and melanoma: Our analysis revealed that TGF-β (encoded by Tgfb1 gene) can be considered as master regulator of aggressive growth and metastasis of B16 melanoma cells: it was found that Tgfb1 was involved in top 10 key nodes, displaying 23 interconnections with partner genes in the network, including other identified key nodes Ccl2, Cd34, Ccl5, Pdgfrb and Col1a2 (Figure 8A, left panel).