T-cells Migration (IMAGE) Max-Planck-Gesellschaft Caption This image depicts a four-day-old zebrafish embryo. The immune cells are illuminated in green; The thymus tissue in red. The eye is visible in the upper part of the picture. Credit Credit: Isabel Hess/Immunity, 16 February 2012 Usage Restrictions None License Licensed content 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.