In an orthotopic mouse xenograft model using luciferase-based bioluminescence imaging to visualize tumors, ErSO induced rapid, near-complete tumor regression in all 3 MCF-7-FGD3 OE tumors by day 3, while ErSO-induced tumor regression in the MCF-7 tumors was more varied at day 3 and largely caught up by day 7. The gene discussed is FGD3; the disease is neoplasm.