Most importantly, we demonstrated that ALDH+ cells performed stronger single cell sphering and migration ability, and demonstrated over-expression of stemness marker proteins CD44, Nanog and Oct-4, and cancer stem cell-associated proteins Bcl-2 and MMP-9, thus indicating some biological characteristics of cancer stem cells, which can be considered as ovarian cancer stem-like cells. This evidence concerns the gene MMP9 and ovarian carcinoma.