CXCR4 and cerebral cavernous malformation: Figure 7(b) shows three representative echocardiograms of hearts receiving CCM, unfractionated ASCs, and CXCR4+ sorted ASCs at four weeks after cell transplantation. LV ejection fraction and fractional shortening were significantly higher in CXCR4+ sorted ASC-treated rats than in unfractionated ASC-treated rats and in CCM control rats (Figures 7(c) and 7(d)).