Table 1.

Different populations of stem cells identified in human renal carcinomas and role in tumor growth. N. D.: not done.

Identification method	Role in carcinogenesis	References
Expression of CD105	Tumor initiation Endothelial differentiation	Bussolati et al. [36]
Expression of CD133	Nontumor initiation Promotion of tumor growth and vascularization	Bruno et al. [33]
Side population	N.D.	Addla et al. [37] Huges et al. [38]
Sphere formation	Tumor initiation Radio- and chemoresistance	Zhong et al. [39]