Congruent with our TBX2 overexpression results in normal breast epithelial cells, RNAi-mediated silencing of TBX2 in two aggressive mesenchymal human breast carcinoma cell lines with endogenous TBX2 overexpression (MDA-MB-435, MDA-MB-157) led to the restitution of a differentiated epithelial tumor phenotype. The gene discussed is TBX2; the disease is breast carcinoma.