Lung entrapment of BMSC. 1–3: Fluorescence microscopic images of lung slices show eGFP+ BMSC as microemboli throughout the entire lung. Cells and cell aggregates can be seen in vascular structures (10×). 4: Higher magnification of image 3. Intravascular cell entrapment and diapedesis into the lung parenchyma (red arrowhead) of CV injected BMSC (40×).