Table 1. Tumorigenic capability of cervical cancer stem cell-like cells in nu/nu mice.

	HeLa				SiHa
# cells	Monolayer	Sphere	ALDH+	ALDH-	Monolayer	Sphere	ALDH+	ALDH-
1×103	0/5	0/5	3/5	0/5	0/5	0/5	4/5	0/5
1×104	0/5	5/5	5/5	0/5	0/5	4/5*	5/5	0/5
1×105	0/5**	5/5***	NT	NT	0/5	5/5**	NT	NT

ALDH+ (ALDH^bright cells: high ADLH activity)

ALDH− (ALDH^low cells: poor ALDH activity)

NT: not tested

^*Tumor growing (≈ 0.5 cm) was observed 30 days after inoculation.

^**Tumor growing (≈ 0.5 cm) was observed in 1/5 mice 60 days after inoculation.

^***Tumor growing (≈ 1 cm) was observed 21 days after inoculation.