HGF and glioma: As we applied ingenuity pathway analysis (IPA) to depict potential pathways populated by the 301 genes, we found that “Glioma Invasiveness Signaling” was the third best-fit pathway based on the differentially-expressed genes between sensitive and insensitive glioma cell lines (Additional file 1: Fig. S2), supporting that HGF-autocrine activation is a strong molecular feature that drives GBM invasiveness.