Cancer stem cells are rare immortal cells within a tumour that can both self-renew by dividing and give rise to many cell types that constitute the tumour, and can therefore form tumors. Such cells have been found in various types of human tumors and might be attractive targets for cancer treatment.
According to this idea, tumors contain:
·Cancer stem cells that divide and feed tumour growth. These cells can self-renew (copy themselves) extensively, and also produce more mature cells called transit amplifying cells.
·Transit amplifying cells that divide a certain number of times then differentiate (or 'mature') into specialized tumour cells.
·Specialized tumour cells that do not divide and so do not contribute to tumour growth.