Abstract
Eradication of cancer stem cells to abrogate tumor growth is a new treatment modality. However, like normal cells cancer cells show plasticity. Differentiated tumor stem cells can acquire stem cell properties when they gain access to the stem cell niche. This indicates that eradicating of stem cells (emptying of the niche) alone will not lead to eradication of the tumor. Treatment should be directed to cancer stem cells and more mature cancer cells.