Here, we show that, indeed, P529 potentiates the effect of RT in the aggressive prostate cancer cell line, PC-3, mainly through the blockade of p-Akt activation, but also through the alteration of other cancer-related pathways involving MMP-2, MMP-9, Id1, and vascular endothelial growth factor (VEGF). The gene discussed is VEGFA; the disease is prostate cancer.