Cancer stem cell: A rogue responsible for tumor development and metastasis.

Cancer stem cells are a small population of cells in a tumor. They have the ability to self-renew and maintain the tumor. The most apt and accepted hypothesis for tumor development is Cancer Stem Cells. This review focuses on this concept of cancer stem cells, serving their purpose and leading to the development of tumor. There are many cell biomarkers which have been described for the identification and characterization of cancer stem cells. The most prominent of the cellular markers for the detection of cancer stem cells; CD133, CD44, ALDH-1 along with some others have been discussed in detail in this review.