Photomicrographs of serial adjacent sections of the left main coronary artery showing codistribution of SSEA-4, Tra-1-60, Oct-4, SSEA-1, SSEA-3, and Tra1-81. SSEA4 positive cells were observed throughout the plaque ((a), scale bar 165 µm) as also shown in Figure 1(d). Clear endothelial-like cells were present overlying the fibrous cap ((b), exploded view, scale bar 33 µm, exploded view scale bar 15 µm); however, not all cells that expressed SSEA-4 codistributed with Oct-4 ((c), scale bar 33 µm, exploded view scale bar 15 µm), although the copresence of endothelial SSEA1/SSEA3 was observed (Figures 2(d) and 2(e), scale bar 33 µm, exploded view scale bar 15 µm). Interestingly, there were no core cells that were positive for Tra1-60 (f) nor Tra1-81 (g) but were scarcely present either overlying the endothelial layer ((f), Tra1-60 insert, scale bar 33 µm, exploded view scale bar 15 µm) or just present beneath the endothelium ((g), scale bar 33 µm, exploded view scale bar 15 µm). Negative control shows no positive signal ((h), scale bar 60 µm, exploded view scale bar 20 µm). As is also observed, no ESC positive spindle shaped cells are present in the fibrous cap.