(A-B) Histological analyses of engrafted cells in the heart sections 4 weeks after EC or UC (1,1∼-dioctadecyl-3,3,3∼,3∼-tetramethylindocarbocyanine perchlorate [Dil]-labeled, red fluorescence) injection. (A) EC had higher retention compared with UC. n = 5 each. *p < 0.05. (B) Confocal microscopic examination demonstrated that injected UC-CD31+ cells (upper panel) or EC-CD31+ cells (lower panel) were colocalized with ILB4 (white arrows) using 3-dimensional z-stacked orthogonal and mul-tipanel images. Arrows indicate colocalized cells and arrowheads, engrafted cells in the perivascular areas. Quantifications of Dil and ILB4-double positive cells are shown on the right. n = 5 each. *p < 0.05. (C-D) Flow cytometry analyses of digested cardiac tissues at 4 weeks. (C) Higher engraftment of EC compared with UC occurred, n = 5 each. *p < 0.05. (D) Quantification of Dil and ILB4 double-positive cells showing a higher rate of endothelial transdifferentiation in EC compared with UC-injected hearts. n = 5 each. *p < 0.05. P1 gating represents ILB4+ fraction and P2 gating double-positive population for Dil and ILB4. DAPI = 4∼,6-diamidino-2-phenylindole. Other abbreviations as in Figures 1 and 5.