We demonstrated that TEPA down-regulated CoCl2-induced EMT regulators, HIF-1α, Snail, and Twist1, which in turn bind to the promoters of their downstream genes including vimentin, fibronectin, and E-cadherin, leading to the reversal of EMT phenotype and decreased migration and invasiveness of human breast carcinoma MCF-7 cells. The gene discussed is TWIST1; the disease is breast carcinoma.