The iMADs express most mesenchymal stem cell markers. Subconfluent iMADs were fixed and stained with antibodies against CD29/integrin β1 (A), CD31/PECAM1 (B), CD73 (C), CD99/Thy-1 (D), CD105/Endoglin (E), CD117/c-Kit (F), CD133/Prom1 (G), or BMPRII (H). All antibodies were obtained from Santa Cruz Biotechnology. Minus primary antibodies and isotype IgG were used as negative controls (data not shown). Cell nuclei were counter-stained with DAPI. Representative images are shown.