Fig. 1.

Impact of CSCs on the effectiveness of anticancer therapy. CSCs are a small sub population of bulk tumor cells that are highly chemo-resistant and play a prominent role in tumor relapse. While conventional therapy results in a transient reduction in the tumor by killing non-stem cancer cells (differentiated cancer cells), the remaining CSCs can form recurring tumors, and metastasis is induced by the formation of a secondary colony in distant organs. The use of CSC-specific inhibitors would reduce therapy resistance and relapse, and prevent metastasis, with a loss of stem cell properties.