ARHGEF4 and cancer: Instead of focusing on the growth of PDACs, the present study showed that retroperitoneal invasion and metastasis to the liver and lung from the PDAC tumors in cancer-bearing nude mice were suppressed by administration of target siRNA-FA-PEG-COL nanoparticles against ARHGEF4, CCDC88A, LAMTOR2, mTOR, NUP85, and WASF2. The key molecules that induce PDAC tumor progression bypass one signal transduction pathway via another pathway.