HGF and hepatocellular carcinoma: In HCC, Yoon et al. [47] indicated that the GRB2-mediated signaling pathway may be involved in tumor progression and differentiation of hepatocarcinoma cells; Kondo et al. [48] reported that coupling of GRB2 to GAB1 could mediate the HGF-induced strong activation of the ERK pathway, which is required for the inhibition of HepG2 cell proliferation.