Cancer is the uncontrolled division of abnormal cells in a tissue. In 1924 German biochemist Otto Warburg discovered that cancer cells exhibit a significantly altered metabolism compared to normal cells (1). One major problem is cancer cells do not properly regulate glucose metabolism and respiration, leading to the profligate consumption of glucose known as the Warburg Effect. It has been hypothesized that the increase in glucose consumption enables the cell to produce more reducing equivalents to detoxify the higher levels of O2 and H2O2 in cancer cells in comparison to normal cell. Excessive levels of these oxidants make cancer cells vulnerable to agents that further increase oxidative stress. We are using agents that increase oxidative stress either by producing more oxidants [declyl-triphenylphosphonium (dTPP)], inhibit the metabolism of H2O2 [Buthionine sulphoximine (BSO), and Auranfin (Aur)], or by inhibiting glycolysis [2-deoxyglucose (2DG)]. In this work we combine these agents in breast cancer cell line MB231 and Sum149 by invitro and in vivo to increase cancer cell killing via oxidative stress.