The cell fate of transplanted adipose tissue-derived stem cells (ASCs) in the liver. (A) Cell tracing after transplantation. Distribution of transplanted ZsGreen-positive cells were found in the liver, spleen, lung, heart, and kidney after delivery through the spleen or femoral vein. More positive cells (black arrow) were observed in the livers of rats 24 hours after intravenous ASC transplantation through the spleen, indicating that the migration rate to the liver was higher through intravenous transplantation. Moreover, a plethora of transplanted cells persisted in the spleen through spleen delivery. Positive cells were observed in the lung but not in the heart and kidney. (B) Double-fluorescence imaging revealed that there was no human albumin (red) or human alpha-fetoprotein (red) expression in the livers, suggesting that transplanted ASCs did not differentiate into hepatocytes. AFP, alpha-fetoprotein; ALB, albumin; DAPI, 4′,6-diamidino-2-phenylindole.