Table 2. Molecular markers of normal adult stem cells in various organs, and their expression in the epididymis without evidence that they are stem cell markers.

	Braina	Liver	Intestine	Kidney	Prostate	Epididymal transcriptb	Epididymal proteinc
	Mouse/human	Human	Mouse/human	Human	Mouse/human	Human	Mouse/bull/human
Abcg2	+					+ (Ref. 20)	Mouse caput epithelial microvilli, caput and corpus interstitial endothelial cells165
Ascl 2			+			+ (Ref. 20)
Bmi-1	+		+
CD9	+					+ (Ref. 20)	Bull corpus and cauda epithelium166
CD24				+		+ (Refs. 20 and 38)
CD29		+					Human cultured cells8
CD44					+	+ (Refs. 20 and 38)	Human cultured cells; mouse basal cells8
CD49b					+
CD49f		+
CD73		+
CD81	+					+ (Refs. 20 and 38)
CD90		+
CD95	+
CD117					+
CD133	+	+		+	+		Human cultured cells (j); mouse principal cells microvilli except initial segment167
CD144	+
CD146	+	+
CD184	+
CK6a					+
DCAMKL-1			+			+ (Ref. 20)
EpCAM		+
Lgr5			+			+ (Ref.20)
Musashi-1			+
mTERT			+
Nestin	+					+ (Ref. 38)
OLFM4			+			+ (Ref. 20)
PTEN			+			+ (Ref. 20)	Mouse caput epithelium apical surface, especially initial segment stereocilia21
Sca-1					+
sFRP5			+			+ (Ref. 20)
SOX4			+			+ (Ref. 20)
SOX9			+			+ (Ref. 20)
WIP1			+
Reference	6	161	162	12	Murine,163, 164	20, 38	8, 21, 165–167
					human13

^aIn neural stem cells not exclusive to adults.

^bExpression reported in human epididymal transcriptome.^{20, 168} No listed markers are found in the proteome.³⁹

^cProtein localized by immunohistology in epididymal cells.