28, 29 We found that knocking down RAC2 decreased PAK4 phosphorylation, and knocking down PAK4 generated similar effects on PCa cell behaviors to RAC2 knock down. Therefore, RAC2 and PAK4 are colocalized in one signaling pathway and miR‐608 could target both of them. In human, PAK4 was upregulated in breast cancer, ovarian cancer, and prostate cancer, where PAK4 exerts tumorigenic effects by enhancing cell proliferation and cell migration.28, 30, 31. The gene discussed is PAK4; the disease is posterior cortical atrophy.