To verify the Grb2 dependence of the ERK activities and oncogenic phenotypes, endogenous Grb2 was silenced (Figure 4A-B) before Grb2WT and Grb2K56R were reintroduced respectively in the murine fibroblast cell line NIH/3T3 (Figure 4C) and the murine colon cancer cell line CMT-93 (Figure 4D) using the lentiviral vector system. Here, GRB2 is linked to colonic neoplasm.