We showed that the presence of the Arf6-based mesenchymal pathway in primary ccRCCs may be easily predicted by immunostaining of proteins such as AMAP1 and its mesenchymal-specific partner EPB41L5; and moreover, we have shown the Arf6-based mesenchymal pathway provide excellent molecular therapeutic targets to block cancer metastasis and to enhance cancer sensitivity to therapeutic drugs (refs 10, 11, 12, 35, and this paper). The gene discussed is ARF6; the disease is cancer.