Representative images of kidney tissue in mice with cisplatin-induced AKI treated with DiI labeled MSCs (day 4). (a) DiI labeled MSCs (red fluorescence) in peritubular area. Original magnification: ×1000. (b) DiI labeled MSCs (red fluorescence) within proximal tubule epithelium. Original magnification: ×1000. Nuclei are stained with DAPI (blue fluorescence). Basal lamina of proximal tubule is marked with a gray line.