Table 1.

Cancer stem cells in solid tumors.

Tumor type	Cells expressing CSC marker (%)	Minimal number of cells expressing marker for tumor formation	Calculated cancer stem cell ratio
Breast	11–35	200	1.1 × 10−3
	ND	2000
	3–10	500
Brain	19–29	100	3.3 × 10−4
	6–21	100
Colon	1.8–25	200	5.4 × 10−4
	0.7–6	3000
	0.03–38	200
Head and neck	0.1–42	5000	4.2 × 10−5
Pancreas	0.2–0.8	100	3.5 × 10−5
	1–3	500
Lung	0.32–22	10,000	1.1 × 10−4
Liver	0.03–6	5000	6 × 10−6

Adapted from Visvader and Lindeman (2008).