EGF and hepatocellular carcinoma: However, in the present study, although EGF stimulation induced β-catenin Ser675 phosphorylation and increased RAP1 expression in vector cells, it failed to rescue RAP1 expression in EYA4-overexpressing cells, indicating that EYA4 might not rely on β-catenin Ser675 phosphorylation to repress RAP1 in HCC.