Human cells in a mouse embryo (image) University at Buffalo Share Print E-Mail Caption This figure shows a large quantity of human cells (labeled green) in a 17-day old mouse embryo (labeled blue). Most of the human cells are red blood cells, which are accumulated in the mouse fetal liver. Credit Zhixing Hu Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.