Table 2. Intestinal stem and cancer stem cell markers.

Marker	Type of crypt cell marked	Proof of stemnessa	Proof of cancer stemness	Number of cells required for tumour growthb
CD24	All lower crypt cells	Organoid growth	Megacolonies Xenotransplant	N/A
CD44	Lower crypt cells except Paneth cells	Expression profile	Megacolonies Xenotransplant	200–500c
CD133	All lower crypt cells	In vivo lineage tracing	Xenotransplant	3000c, 262d
CD166	Intercalated crypt base cells and Paneth cells	Expression profile Immunofluorescence FACS	Xenotransplant	1000–4000c
Lgr5	Intercalated crypt base cells	In vivo lineage tracing	Targeted Apc deletion	N/A
Olfm4	Intercalated crypt base cells	In situ hybridisation	In situ hybridisation	N/A
Aldh1	Isolated crypt base cells	Immunofluorescence	Xenotransplant	25e
Integrins	All lower 1/3 crypt cells (β1 integrin)	Colony forming assay	N/A	N/A
Bmi1	+4 Single supra-Paneth cell	In vivo lineage tracing	N/A	N/A
Musashi1	Intercalated crypt base and supra-Paneth cells	Immunohistochemistry	N/A	N/A

Abbreviations: FACS=fluorescence-activated cell sorting; NOD/SCID=non-obese diabetic/severe combined immunodeficient.

^aStrongest evidence quoted.

^bIn NOD/SCID mice.

^cDalerba et al (2007).

^dO’Brien et al (2007).

^eHuang et al (2009).