These low nanomolar concentrations of genistein have been shown to bind to and inhibit MEK4 (MKK4/MAP2K4) kinase, thereby inhibiting the following pro-metastatic pathway in human PCa cells: MEK4 → p38 MAPK → MAP2K4 → HSP27 → MMP-2 → cell invasion → metastasis [2, 3, 5–9]. The gene discussed is MAP2K4; the disease is posterior cortical atrophy.