In order to explore further the mechanisms by which knock down of TIMP-2 increased chemosensitivity in OVCAR4 cells, we evaluated the expression of two chemoresistance markers, DNA excision repair complex protein 1 (ERCC1) and tubulin β type III (TUBB3), and cancer stem cell (CSC) markers [Pou5f1 (OCT4), CD44, CD133 and EpCAM)] at the mRNA and protein levels. The gene discussed is POU5F1; the disease is cancer.