A primary observation in the present study is that both GEP100 siRNA and PH domain deletion mutant GEP100-△PH transfection can significantly inhibit EGF-induced migration as well as membrane ruffling of HepG2 cells, indicating that GEP100, especially its PH domain, serves as a key mediator of EGF-stimulated migration of these cancer cells. This evidence concerns the gene EGF and cancer.