Table 1.

Required cell surface epitope profile for a population of MSCs [28].

Surface marker	Protein name	Indicator for HSC*
≥95% of the cell population must be positive for
CD73	ecto-5′-nucleotidase (SH3 and SH4)	Non-specific
CD90	thy-1	Non-specific
CD105	endoglein (SH2)	Non-specific
≤98% of the cell population must be negative for
CD34	Unknown antigen	Primitive hematopoietic progenitors and endothelial cells
CD45	Protein tyrosine phosphatase receptor type C	Pan-leukocyte marker
CD14 or CD11b‡	Unknown antigen or integrin α M	Monocytes and macrophages
CD79α or CD19‡	Immunoglobulin-associated α or unknown antigen	B-cells
HLA-DR§	MHC class II (heterodimer)	Immunologically simulated cells

^*HSC: Hematopoietic stem cell.

^‡Either marker is sufficient for the given requirement.

^§Cells positive for HLA-DR may still be considered MSCs, but this marker indicates that they have been stimulated (e.g., by IFN-γ), which should be indicated when describing the cell type (i.e., as ‘stimulated’ MSCs).

The proteins associated with CD34, CD19 and CD19 are currently unknown.