Morphology of rhesus monkey ES cell–derived endothelial cells (RESDECs). (A-B) Rhesus ES cells were grown in EGM2 media and then transferred to a new tissue-culture plate where uniform flat, adherent, stellate-appearing cells were demonstrated. (C-D) RESDEC cells were made into a single-cell suspension and transferred to a Matrigel-coated plate where capillary tube–like structures were seen within 18 hours after transfer. Original magnifications: × 100 (A,D); × 200 (B); and × 40 (C).