PEDF activates the ERK signaling pathway, as indicated by ERK1/2 phosphorylation in mesenchymal stem cells, primary neurons and muscle progenitor cells.36, 37, 38 More importantly, there was a positive correlation between PEDF expression levels and N-cadherin in HCC tissues, and a high co-expression of PEDF and N-cadherin predicted a poorer prognosis. The gene discussed is MAPK3; the disease is hepatocellular carcinoma.