Interestingly, while U0126 had no effect on the tumor growth, invasion, and lung infiltration for A549 tumors, it significantly suppressed all these phenotypes in GFI1-expressing A549 tumors and H1155 tumors (Figure 5, E–G), indicating that GFI1-caused tumor invasion and metastasis resulted from GFI1-induced ERK activation. Here, GFI1 is linked to neoplasm.