Abstract
There is increasing evidence that malignant tumor is driven by tumorinitiating cells or cancer stem cells (CSCs) have recently attracted a great number of considerations for novel cancer therapy. The concept of cancer stem cell (CSCs) is an appealing model to describe the functional heterogeneity of tumor cells. It suggests a hierarchical organization of CSCs subpopulation to sustain tumor growth and metastasis. CSCs could be resistant to standard anti-cancer drugs, which might describe the limitations of these therapies. So, much work is required to identify and use of CSCs as a target for anti-cancer treatment. This chapter focuses on the recent advances in the cancer stem cell field and anticancer drug discovery.