Figure 3.

The involvement of the ERK pathway in the TGF-β-induced epithelial-mesenchymal transition. After TGF-β induces the phosphorylation of serine and/or tyrosine on TβRI and/or ShcA, ShcA is capable of recruiting Grb2 and Sos to active ERK1/2 through Ras, Raf, and MEK1/2. The activation of Ras can also be induced by HGF to control the EMT, which is regulated by Snail. This figure depicts the cross-talk between ERK, TGF-β, and other factors in different cellular systems and illustrates how these networks may function in a stimuli-dependent manner to determine the EMT response.