When combined with metformin, quercetin strongly inhibits the growth, migration, and invasion of prostate cancer cells both in vitro and in vivo through the vascular endothelial growth factor/AKT8 virus oncogene cellular homolog/phosphatidylinositol-3-kinase (VEGF/Akt/PI3K) signaling pathway (47). The gene discussed is AKT1; the disease is prostate cancer.