Table 1.

Identification and validation success rates of CSC markers in ovarian cancer

Putative CSC marker	Putative CSCs identified	CSCs validated	Screened only (references)	Screened and validated (references)
CD133+	10 of 11	5 of 5	[25, 27, 29–31]	[28, 32–35]*
ALDH+	4 of 4	4 of 4		[25, 27, 28, 33]*
HSP+	4 of 4	4 of 4		[31, 36–38]
CD44+	12 of 12	1 of 2	[27–32, 36, 39]	[33, 40]
CD117+	7 of 11	1 of 2		[33, 40]
CD24+	7 of 7	1 of 1	[25, 28, 31, 32, 36]	[41]
CD24-	1 of 1	1 of 1		[30]
ABCG2+	2 of 3	0 of 2	[30]	[28, 38]

This table is ranked from top to bottom by the most frequently validated ovarian CSC markers. CSC validation is classified as a demonstration of increased xenograft tumorigenicity in the respective studies. Most studies screened for multiple CSC markers, while only bringing a sub-set forward for validation. This table makes the distinction between markers that were ‘screened only’ and those that were ‘screened and validated’ in the respective studies.

*[33] found that CD133+ and ALDH+ putative CSCs validated as CSCs in most but not all of the patients tested. In other patients there was no significant difference between CD133+ and CD133- or ALDH+ and ALDH- cells in tumorigenicity. Additionally, in a small sub-set of patients CD133- not CD133+ cells were identified as CSCs.