Table 1.

Summery of reported cardiac stem/progenitor cells

	Surface Markers	Gene Expression	Self renewal	In-vitro differentiation	In-vivo differentiation	Species	Reference
SP	Sca-1+, CD31+, CD34 -, c-kit-*, CD45-, Isl1-	Nkx2.5, GATA4, MEF2C, Tie2	Yes	CM, CE, SMC	CM, EC	Mice, pig, human	Hierlihy et al 2002 18 Pfister et al 2005 15 Mouquet et al 2005 49 Martin et al 2004 13 Messina et al 2003 14
c-kit	Sca-1+, SP+** Lin-, CD45-, CD31-, CD34-	Nkx2.5, GATA4, MEF2C	Yes	CM, EC, SMC	CM, EC, SMC	Mice, rat, dog, pig, human,	Urbanek et al 2003 107 Beltrami et al 2003 12 Linke et al 2005 108
Sca-1	CD31+, CD34- Lin-, CD45-, c-kit-***	Nkx2.5***, GATA4, MEF2C, Tie2	ND	CM	CM	Mice, dog	Oh et al 2003 19 Matsuura et al 2004 109
Isl-1	Lin-, CD45-, c-kit-, CD34-, CD31-, SP-	Nkx2.5, GATA4	Yes	CM	ND	Mice, rat, human	Laugwitz et al 2005 20

CM: cardiomyocyte. EC: endothelial cell. SMC: smooth muscle cell. ND: not determined

^*C-kit might be cleaved by cardiac tissue enzymatic digestion. Martin et al found no expression of CD31, while Pfister et al reported two sub populations of CD31+ and CD31- among CSP. These differences may due to slight variation in isolation procedures used between groups.

^**SP phenotype was not addressed through Hoechst exclusion but through MDR-1 expression.

^***Matsuura et al reported 40% and 10% of Sca-1 cells expressing CD45 and CD34, respectively.